wandering spider range

Brazilian wandering spiders: Bites & other facts

Brazilian wandering spiders don't build webs but crawl on the forest floor at night in search of prey, which they kill with neurotoxic venom.

Classification/taxonomy

Size & characteristics, bites and venom, additional resources.

Brazilian wandering spiders are aggressive spiders that belong to the genus Phoneutria, which means "murderess" in Greek.

These critters, also known as armed spiders or banana spiders, are some of the most venomous spiders on Earth. Their large mouthparts, or chelicerae, inflict painful bites loaded with neurotoxic venom that can be deadly to humans — especially children — although in most cases immediate medical care can prevent death with antivenom, according to a 2018 study in the journal Clinical Toxinology in Australia, Europe, and Americas .

Brazilian wandering spiders are frequently listed among the deadliest spiders in the world . They were named the world's deadliest spiders multiple times by Guinness World Records, although the current record-holder is the male Sydney funnel-web spider ( Atrax robustus ). But "classifying an animal as deadly is controversial," Jo-Anne Sewlal, an arachnologist at the University of the West Indies in Trinidad and Tobago, previously told Live Science. Each bite is unique, and the damage it causes depends on the amount of venom injected, Sewlal said. 

Jo-Anne Sewlal was a noted arachnologist from Trinidad and Tobago. While completing her PhD, she received the National Institute of Higher Education, Research, Science and Technology (NIHERST) 2012 Award for Excellence in Science and Technology for Junior Scientist. In 2013, She received a doctorate in zoology from the University of the West Indies. She discovered several species of spiders in her home country, surveyed the arachnids across several countries the Caribbean and appeared as an expert on the topic on The Science Channel. She died of an allergic reaction in January 2020.

There are nine species of Brazilian wandering spider, all of which are nocturnal and can be found in Brazil. Some species also can be found throughout Central and South America, from Costa Rica to Argentina, according to a 2008 article in the journal American Entomologist . Study author Richard S. Vetter , a research associate in the department of entomology at the University of California, Agriculture and Natural Resources, wrote that specimens of these powerful arachnids have been mistakenly exported to North America and Europe in banana shipments. However, Vetter noted, in many cases of cargo infestation, the spider in question is a harmless banana spider (genus Cupiennius ) that is misidentified as a Phoneutria . The two types of spiders look similar.

The taxonomy of Brazilian wandering spiders, according to the Integrated Taxonomic Information System (ITIS) , is:

Kingdom : Animalia 

Subkingdom : Bilateria 

Infrakingdom : Protostomia 

Superphylum : Ecdysozoa 

Phylum : Arthropoda 

Subphylum : Chelicerata 

Class : Arachnida 

Order : Araneae 

Family : Ctenidae 

Genus : Phoneutria  

• Phoneutria bahiensis
• Phoneutria boliviensis
• Phoneutria eickstedtae
• Phoneutria fera
• Phoneutria keyserlingi
• Phoneutria nigriventer
• Phoneutria pertyi
• Phoneutria reidyi
• Phoneutria depilata , according to a 2021 study published in the journal ZooKeys , which found that Phoneutria boliviensis actually included two separate species from different habitats. 

Brazilian wandering spiders are large, with bodies reaching up to 2 inches (5 centimeters) and a leg span of up to 7 inches (18 cm), according to the Natural History Museum in Karlsruhe, Germany. The species vary in color, though all are hairy and mostly brown and gray, although some species have lightly colored spots on their abdomen. Many species have bands of black and yellow or white on the underside of the two front legs, according to the University of Florida . 

These arachnids "are called wandering spiders because they do not build webs but wander on the forest floor at night, actively hunting prey," Sewlal told Live Science in an interview conducted in 2014, before her death. They kill by both ambush and direct attack.

They spend most of their day hiding under logs or in crevices, and come out to hunt at night. They eat insects, other spiders and sometimes, small amphibians, reptiles and mice. 

Research into one species of Brazilian wandering spider, Phoneutria boliviensis , revealed that these spiders eat a mix of arthropods and reptiles. DNA metabarcoding, a technique that examines the DNA and RNA in a sample, of the guts of 57 spiders identified 96 prey species, including flies, beetles, butterflies, moths, grasshoppers, locusts and crickets, according to research from the University of Tolima and the University of Ibagué in Colombia . Some of the female spiders also ate lizards and snakes.

While their bites are powerful and painful, "their bites are a means of self-defense and only done if they are provoked intentionally or by accident," Sewlal said.

When Brazilian wandering spiders feel threatened, they often assume a defensive position by standing on their hind legs and stretching out their front legs to expose their fangs, according to the 2018 study in Clinical Toxinology in Australia, Europe, and Americas. This posture is sometimes accompanied by side-to-side movements. The spiders can also jump distances up to 1.3 feet (40 cm). 

In the Brazilian wandering spider, just as in most spider species, the female is larger than the male. Males approach females cautiously when attempting to mate, according to the biology department at the University of Wisconsin-La Crosse . Males perform a dance to get females' attention, and males often fight each other over the female. The female can be picky, and she often turns down many males before choosing a mating partner. Once she does pick one, the male needs to watch out; females often attack the males once copulation is finished.

The female then can store the sperm in a separate chamber from the eggs until she is ready to fertilize them. She will lay up to 1,000 eggs at a time, which are kept safe in a spun-silk egg sac.

Brazilian wandering spiders typically live for one or two years.

Brazilian wandering spiders' venom is a complex cocktail of toxins, proteins and peptides, according to the Natural History Museum in Karlsruhe, Germany. The venom affects ion channels and chemical receptors in victims' neuromuscular systems.

After a human is bitten by one of these spiders, they may experience initial symptoms such as severe burning pain at the site of the bite, sweating and goosebumps, Sewlal said. Within 30 minutes, symptoms become systemic and include high or low blood pressure , fast or a slow heart rate , nausea, abdominal cramping, hypothermia, vertigo, blurred vision, convulsions and excessive sweating associated with shock. People who are bitten by a Brazilian wandering spider should seek medical attention immediately.

Their venom is perhaps most famous for triggering painful and long-lasting erections . For that reason, in a 2023 study, scientists reported that they were testing the venom in humans as a potential treatment for erectile dysfunction in those for whom Viagra didn't work.

However, these bites are rare, and envenomations, or exposure to these toxins from a spider bite, are usually mild, Vetter said. For instance, a 2000 study in the journal Revista do Instituto de Medicina Tropical de São Paulo found that only 2.3% of people with bites who came to a Brazilian hospital over a 13-year period were treated with antivenom. (The other bites did not contain enough venom to require it.) Most of the bites were from the species P. nigriventer and P. keyserlingi in eastern coastal Brazil. About 4,000 bites reportedly happen each year in Brazil, but only 0.5% of those cases are severe, according to the 2018 study. Meanwhile, 15 deaths have been attributed to Phoneutria in Brazil since 1903, the 2018 study reported. 

"It is unlikely that the spider would inject all of its venom into you, as this venom is not only needed as a means of defense but to immobilize prey," Sewlal said. "So if it did inject all of its venom, it [would] have to wait until its body manufactured more before it could hunt." That would also leave the spider vulnerable to being attacked by predators.

Furthermore, Sewlal pointed out that venom production requires a lot of a spider's resources and time. "So if the spider were to attack frequently and use up all of its venom, it [would] be safe to assume that it has a ready food supply to replace the energy and resources used. This situation does not exist in the wild."

• Learn more about Brazilian wandering spiders from the University of Wisconsin-La Crosse .
• Read about several species of Brazilian wandering spiders, including several images of the arachnids at the University of Florida .
• Find a spider in your bananas? It may or may not be a deadly species, according to the University of California, Riverside .

This article was originally published on Nov. 20, 2014. 

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Jessie Szalay is a contributing writer to FSR Magazine. Prior to writing for Live Science, she was an editor at Living Social. She holds an MFA in nonfiction writing from George Mason University and a bachelor's degree in sociology from Kenyon College. 

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• Sascha Pare Trainee staff writer

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Brazilian Wandering Spider

The Brazilian Wandering Spider (Phoneutria fera) is an aggressive and highly venomous spider . It was first discovered in Brazil hence its name. However, this genus is known to exist elsewhere in South and Central America .

The Brazilian Wandering spider is a member of the Ctenidae family of wandering spiders.

The Brazilian Wandering spider appeared in the Guinness Book of World Records 2007 for being the most venomous animal .

In this particular genus, there are five known similar species whose members are also highly venomous. They include some of the relatively few species of spiders that present a threat to human beings.

Brazilian Wandering Spider Characteristics

The Brazilian wandering spider can grow to have a leg span of up to 4 – 5 inches. They are large hairy spindly-looking spiders who have eight eyes, two of which are large. Brazilian wandering spiders are fast-moving spiders, their legs are strong and spiny and they have distinctive red jaws which they display when angered.

The Brazilian wandering spider is not a Tarantula . Brazilian wandering spiders are not even in the same family group. Tarantulas are harmless to humans and are mostly ambush killers who wait for prey to come to them. Brazilian wandering spiders are active hunters. Brazilian wandering spiders and Tarantulas do have one thing in common, however, they do not eat bananas.

Brazilian Wandering Spider Habitat and Spider Webs

The Brazilian Wandering spider is so-called because it wanders the jungle floor, rather than residing in a lair or maintaining a web. This is another reason it is considered so dangerous. In densely populated areas, the Brazilian Wandering spider will usually search for cover and dark places to hide during daytime, leading it to hide within houses, clothes, cars, boots, boxes and log piles. This usually causes accidents when people disturb them.

The Brazilian Wandering spider is also called the ‘banana spider’ as it is occasionally found within shipments of bananas. As a result, any large spider appearing in a bunch of bananas should be treated with due care.

Brazilian Wandering Spider Diet

Adult Brazilian Wandering spiders eat crickets, other large insects, small lizards and mice. Spiderlings of this species eat flightless fruit flies and pinhead crickets.

Brazilian Wandering Spider Reproduction

All spiders produce silk, a thin, strong protein strand extruded by the spider from spinnerets most commonly found on the end of the abdomen. Many species use it to trap insects in webs, although there are many species that hunt freely such as the Brazilian Wandering spider. Silk can be used to aid in climbing, form smooth walls for burrows, build egg sacs, wrap prey and temporarily hold sperm, among other applications.

Brazilian Wandering spiders reproduce by means of eggs, which are packed into silk bundles called egg sacs. The male spider must (in most cases) make a timely departure after mating to escape before the females normal predatory instincts return.

Mature male spiders have swollen bulbs on the end of their palps for this purpose and this is a useful way to identify whether the spider is male or female. Once the sperm is inside the female spider, she stores it in a chamber and only uses it during the egg-laying process, when the eggs come into contact with the male sperm for the first time and are fertilized. The Brazilian Wandering spiders life cycle is 1 – 2 years.

Brazilian Wandering Spider Venom

Bites from the Brazilian Wandering spider may result in only a couple of painful pinpricks to full-blown envenomed. In either case, people bitten by this spider or any Ctenid should seek immediate emergency treatment as the venom is possibly life threatening.

The Phoneutria fera and Phoneutria nigriventer (two species of wandering spider) are the two most commonly implicated as the most vicious and deadly of the Phoneutria spiders.

The Phoneutria not only has a potent neurotoxin, but is reported to have one of the most excruciatingly painful envenoms of all spiders due to its high concentration of serotonin. They have the most active venom of any living spiders.

One of their members, the Brazilian Huntsman, is thought to be the most venomous spider in the world. Brazilian wandering spiders are certainly dangerous and bite more people than any other spiders.

Check out more  animals that begin with the letter B

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About joanne spencer.

I've always been passionate about animals which led me to a career in training and behaviour. As an animal professional I'm committed to improving relationships between people and animals to bring them more happiness.

Understanding the Wandering Spider: Quick Essential Facts

Wandering spiders are a group of venomous arachnids found primarily in South America.

Among these, the Brazilian wandering spider is particularly known for its potent venom and unique behavior. They are often referred to as “banana spiders” due to their frequent encounters with humans in banana plantations.

As a reader, you might be interested in learning more about these fascinating creatures, including their habitat, hunting techniques, and the effects of their venom.

In this article, we will delve into the world of wandering spiders and provide you with all the essential information to satisfy your curiosity.

Scientific Classification and Naming

The wandering spider belongs to the genus Phoneutria , which is a part of the Ctenidae family.

These spiders are known for their potent venom and aggressive behavior. Here is the scientific classification of the wandering spider:

• Kingdom: Animalia
• Phylum: Arthropoda
• Subphylum: Chelicerata
• Class: Arachnida
• Order: Araneae
• Family: Ctenidae
• Genus: Phoneutria

Within the genus Phoneutria, two species are particularly noteworthy: Phoneutria fera and Phoneutria nigriventer, also known as P. nigriventer . These spiders are primarily found in South America and other tropical regions.

Phoneutria fera and P. nigriventer differ in some aspects. Let’s compare their features using a table:

Some key characteristics of the wandering spiders in the genus Phoneutria include:

• Potent venom that can be dangerous to humans
• Nocturnal hunters and are active at night
• Equipped with long, spiny legs for capturing prey
• Aggressive defenders of their territory

By understanding the scientific classification and differences between Phoneutria species, you can better appreciate the diversity and fascinating biology of these wandering spiders.

Identification and Appearance

Color and size.

The wandering spider, also known as the banana spider, has a distinctive appearance that can help you easily identify it in the wild.

They usually have a combination of hairy brown and black colors on their body. Their size can vary, but they are generally considered large spiders. Their size can range from 1 to 2 inches in body length.

When it comes to wandering spider’s leg span, these creatures can have an impressive reach. Their leg span can extend up to 5-6 inches.

Some key characteristics of a wandering spider’s legs include:

Habitat and Distribution

Wandering Spiders are known to inhabit various environments, including rainforests and tropical forests.

These spiders can adapt to different habitats based on their needs and availability of food sources. They prefer warm and humid places, as these conditions suit their growth and reproduction.

Geographical Coverage

Wandering spiders are found in Central and South America .

They live in forests from Costa Rica to Argentina, including Colombia, Venezuela, The Guianas, Ecuador, Peru, Bolivia, Brazil, Paraguay, and Northern Argentina.

They may also be present in some parts of the United States, particularly in the northern part of southern America.

However, they don’t inhabit countries like Australia. In summary, the Wandering Spider is mostly prevalent in the following areas:

• South America
• Central America
• Southern parts of the United States

Types of Wandering Spiders

Here’s a brief description of the major types of wandering spiders.

Brazilian wandering spiders

Also known as armed or banana spiders, these spiders are nocturnal and don’t make webs.

They are known to have been transported outside of South America in banana shipments.

Phoneutria nigriventer

These spiders contain neurotoxins that can cause cerebral changes and breakdown of the blood-brain barrier .

Their venom is medically significant and has been used in manufacturing drugs. Their bites may be fatal to children.

Ctenus captiosus

Also known as the Florida false wolf spider or tropical wolf spider, this species is found in the United States.

Some species of these spiders are large and scary-looking, but they’re only mildly venomous. Their venom is comparable to a bee sting.

Other types of wandering spiders include: Acantheis, Acanthoctenus, Africactenus, and Afroneutria.

Behavior and Diet

Aggression level.

Wandering spiders, as their name suggests, are known for their aggressive behavior .

While they won’t attack without provocation, if they feel threatened, they will not hesitate to defend themselves.

This is especially true during mating season.

Prey and Predators

In their natural habitat, wandering spiders primarily feed on insects and small vertebrates, such as:

• Insects like ants and moths
• Small amphibians

This diverse diet allows them to thrive in various ecosystems.

However, they are not top predators, as their natural predators include larger birds, mammals, and other spiders.

Nocturnal Activities

Wandering spiders are nocturnal creatures , which means they are active during the night.

During the day, they remain hidden in their retreats, often made from rolled-up leaves or small crevices.

At night, they leave their hiding spots to search for prey using their strong hunting skills.

Venom and Its Effects

Composition of venom.

The venom of the wandering spider is a complex mixture containing several toxic components.

Its main component is a potent neurotoxin, which can have severe effects on your nervous system 1 . Here’s a brief overview of its composition:

• Neurotoxins

Symptoms and Severity

A wandering spider’s venomous bite can cause a wide range of symptoms, depending on the severity of envenomation. These symptoms may include 2 :

• Mild to moderate pain
• Redness and swelling at the bite site
• Irregular heartbeat
• Difficulty breathing
• Blurred vision
• High blood pressure

Some severe cases may result in life-threatening complications, such as respiratory failure or even death 2 .

Medical Treatment and Antivenom

If bitten by a wandering spider, it’s crucial to seek immediate medical attention. Treatment often involves the following steps:

• Cleaning and immobilizing the affected area
• Monitoring and managing the symptoms
• Administering antivenom if it’s available and appropriate, depending on the severity of envenomation 3

Antivenom is specific to the venom of the wandering spider and can help neutralize its effects.

However, the availability of antivenom may be limited in some regions 3 .

Always remember that prevention is better than cure: learning how to identify and avoid wandering spiders is the best way to stay safe.

Reproduction and Mating

Mating ritual.

When it’s time for reproduction, the wandering spider undergoes an intriguing mating ritual.

The male spider performs a dance to attract the female by displaying his brightly colored legs and vibrating his body.

During the process, the male also produces a sperm web and transfers his sperm to the female’s reproductive organs using his pedipalps.

Egg Sacs and Offspring

After the mating process, the female wandering spider will create an egg sac to protect her eggs.

The sac consists of silk and can hold hundreds of eggs. She then attaches it to a safe hiding place, usually against a protective surface or within a secure web.

The female often guards the egg sac to ensure the protection of her offspring until they hatch.

Once the spiderlings hatch, they are known to be highly independent.

They disperse quickly and start their own journey, fending for themselves soon after emerging from the egg sac.

As they grow, they’ll go through a series of molts before reaching adulthood and beginning their own reproductive cycle.

Danger and Defense Mechanisms

The Wandering Spider is known to be one of the most dangerous spiders in the world.

Although they can potentially kill humans, fatalities are rare due to their reluctance to bite.

Oddly enough, their venom can cause an involuntary erection in men, alongside other painful symptoms.

Here are some ways the Wandering Spider protects itself and displays its dangerous nature:

• Fangs : These spiders are equipped with strong, sharp fangs that can easily pierce human skin, allowing them to inject their venom with ease.
• Venom : Their venom is potent and can cause severe pain, inflammation, and other adverse effects. In rare cases, it can even lead to death.

While interacting with Wandering Spiders, be cautious and observe them from a safe distance.

Knowing their defense mechanisms will help you respect their space and avoid any unpleasant encounters.

Remember, it’s essential to be informed and aware when dealing with these fascinating, yet dangerous creatures.

Comparison with Other Dangerous Spiders

Comparison to black widow.

The black widow spider is notorious for its potent venom, but the wandering spider has a stronger venom overall.

Both spiders are capable of causing severe symptoms, but the black widow’s venom is primarily neurotoxic, affecting your nervous system.

In contrast, the wandering spider’s venom can cause both neurotoxic and cytotoxic effects, potentially damaging your nerves and cells.

• Potent neurotoxic venom
• Red hourglass marking
• Stronger venom (neurotoxic and cytotoxic)
• No distinct marking

Comparison to Brown Recluse

The brown recluse spider is known for its necrotic venom that can lead to tissue damage and sometimes requires medical intervention.

While both the brown recluse and wandering spider can produce venomous bites, wandering spiders are considered more dangerous due to the potency of their venom and the severity of their bite symptoms.

• Necrotic venom
• Dark violin-shaped marking

Comparison to Wolf Spider

Wolf spiders are frequently mistaken for more dangerous spiders due to their size and appearance.

Although they can bite, their venom is not particularly potent and generally only causes mild itching, redness, and swelling.

In comparison, the wandering spider’s venom is far more dangerous, and its bite can result in serious symptoms, requiring immediate medical attention.

• Large and hairy
• Smoother appearance

Comparison to Sydney Funnel-Web Spider

The Sydney funnel-web spider is another highly venomous spider known for its potentially lethal bites.

While both spiders possess powerful venom, the wandering spider has a broader range of symptoms due to the combination of neurotoxic and cytotoxic effects.

In conclusion, wandering spiders are more dangerous than wolf spiders but their venom’s effects are more varied compared to black widows, brown recluses, and Sydney funnel-web spiders.

Be cautious around these spiders and seek medical help if bitten.

Interesting Facts and Guinness World Records

The Wandering Spider, also known as the Brazilian Wandering Spider, is a fascinating creature that has caught the attention of many.

They belong to the genus Phoneutria , which means “murderess” in Greek, giving you an idea of their potency. Let’s explore some interesting facts about this spider and its place in the Guinness World Records.

First, you might be curious about their venom. The Wandering Spider is known for having one of the most potent venoms among spiders.

In fact, it holds the Guinness World Record for the most venomous spider. Their venom contains a potent neurotoxin that can cause severe symptoms, including difficulty breathing, high blood pressure, and intense pain.

Apart from their venom, their behavior is also quite intriguing. These spiders are called “wandering” because they are known for actively hunting their prey rather than spinning webs to catch them.

They are mostly nocturnal creatures and, during the day, can be found hiding in logs or dark crevices.

Here are a few more notable characteristics of the Wandering Spider:

• Females are larger than males, with a body length of up to 1.6 inches (4 cm).
• They have eight eyes, arranged in two rows, which help them in hunting.
• The Wandering Spider is primarily found in Central and South America, particularly in Brazil.
• They are known to show aggression when threatened.

While the Wandering Spider is a marvel of the arachnid world, it’s essential to keep a safe distance from them due to their venomous nature.

However, their unique characteristics and record-breaking venom potency make them a fascinating subject for those interested in the natural world.

Prevention and Safety Measures

To protect yourself from wandering spiders, there are some simple safety measures you can take.

Firstly, be cautious in areas where these spiders may live, such as dark and warm spaces. For example, avoid reaching into crevices or lifting piles of wood without inspecting them first.

Always wear appropriate shoes when outdoors, particularly in wooded or grassy areas. This can help prevent bites on your feet or ankles.

Reduce the risk of wandering spiders entering your home by sealing gaps and cracks. This minimizes the chance of the spiders finding a way inside.

Regularly clean your living spaces, paying special attention to dark and hidden areas. By maintaining a clean environment, you’ll discourage wandering spiders from making themselves at home.

When out in nature, avoid disturbing spider habitats like webs or egg sacs. This can prevent agitating wandering spiders, reducing your chance of accidental encounters.

Remember, wandering spiders can be dangerous, but by taking these precautions, you can significantly reduce your risk of encountering them or being bitten. Stay safe and always be aware of your surroundings.

In summary, wandering spiders, particularly those in the genus Phoneutria, are a group of venomous arachnids predominantly found in Central, South America and parts of Southern United States.

These spiders, including the Brazilian wandering spider, are known for their potent venom, nocturnal hunting habits, and aggressive defense mechanisms.

Their venom, containing neurotoxins and other components, can cause severe symptoms in humans, making them one of the most dangerous spider species.

Despite their fearsome reputation, fatalities are rare, and they play a vital role in their ecosystems.

It’s important to respect their space and take preventive measures to avoid encounters. Understanding these spiders’ behavior, habitat, and characteristics can help in appreciating their role in nature while ensuring safety.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2857337/ ↩

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3851068/ ↩ ↩ 2

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6560916/ ↩ ↩ 2

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about wandering spiders. Scroll down to have a look at some of them.

Letter 1 – Wandering Spider from Ecuador

Hi Michele, There is a resemblance to the Dolomedes Fishing Spiders, and finding it near a river lends credence to that possibility. Eric Eaton noticed this posting and has this to say: ” Ok, the spiders from Ecuador and Costa Rica: They are most likely NOT wolf spiders, but wandering spiders, either in the family Ctenidae or Sparassidae. They tend to be more common, and even larger than, wolf spiders in the tropics. At least one species, Phoneutria fera, is extremely aggressive, with potentially deadly venom. Do not mess with large spiders in Central and South America! The venomous types are very difficult to distinguish from harmless species, and in any event, a bite is going to be really painful. These spiders sometimes stow away in bananas, houseplants, and other exported goods, so they can show up in odd places. Be careful where you put your hands.”

Update:  May 14, 2013 We now have a confirmation that this is a Wandering Spider, Phoneutria fera , and it is a dangerous species.  See Encyclopedia Britannica and Animal Corner .

Letter 2 – Brazilian Wandering Spider: Most Venomous Animal

Hi Martin, We are happy you were able to write to us after your encounter with this Brazilian Wandering Spider and are thrilled to be able to post your story and photos to our site. We started to research, and our first hit has a different species name. Phoneutria fera is described as: “The Brazilian Wandering Spider is not for the ‘pet keeper’. Brazilian Wandering Spiders are extremely fast, extremely venomous, and extremely aggressive. These large and dangerous true spiders are ranked among the most venomous spiders known to man. In fact, the Brazilian Wandering Spider is the most venomous spider in the New World! In South America, these true spiders are commonly encountered in peoples’ homes, supposedly hiding in peoples’ shoes, hats, and other clothes. The Brazilian Wandering Spider does not remain on a web, rather, it wanders the forest floor, hence the name.” Our favorite information on Wikipedia is that Phoneutria is Greek for “murderess”. Here is one final tidbit about the effect of the bite of the Brazilian Wandering Spider on the human male .

Letter 3 – Possibly Wandering Spider from Ecuador

Dear Mike, This is really an interesting Spider, but other than to say it appears to be a hunting spider that does not build a web to entrap prey, we aren’t sure about its identity.  Many hunting spiders can jump quite well.  It looks very much like the spider in a posting in our archives, also from Ecuador, that we identified as possibly a Wandering Spider in the genus Phoneutria, a venomous and potentially dangerous genus .  The spotted legs on your individual look like the spotted legs on an individual in an image on Wikipedia of a Wandering Spider in the genus Phoneutria .  There are many images of Brazilian Wandering Spiders on Primal Shutter and we believe that might be a correct identification for your individual.

Thank you for the information.  After reading more about the spider, I’m glad it didn’t jump! Mike

Letter 4 – Possibly Wandering Spider from Ecuador

Dear Carl, We believe, though we are not certain, that this might be a Wandering Spider in the genus Phoneutria, and you may read more about Wandering Spiders on the Museum für Naturkunde Karlsruhe website where it states:  “There is no doubt that the venom of some of the species is quite potent for mammals, including humans.”  We eagerly welcome additional opinions on this identification.  Perhaps Cesar Crash of Insetologia can provide something.  In the future, please submit a single species per submission form as it makes it extremely difficult for us to categorize postings with multiple species.

Letter 5 – Wandering Spider from Belize

Hi Karl, Thanks for allowing us to post your excellent image of a Wandering Spider, Cupiennius salei .  The species is pictured on iNaturalist .

Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page .

Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

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8 comments . leave new.

Hi Michele, I am an Ecuadorian scientist and specialized on spiders, I would like to find one like yours, I can say that, almost without doubt, you found the Phoneutria itself, it is the Phoneutria fera, look at this picture: http://www.google.com/imgres?imgurl=http://4.bp.blogspot.com/-bFH9qzT0F7U/T_2sZuk6xAI/AAAAAAAAAGY/8jnMVcPOcNI/s1600/phoneutria_fera2.jpg&imgrefurl=http://rangerbaiano.blogspot.com/2012/07/animais-peconhentos-e-venenosos.html&usg=__iCWEz7S86xub6RAyvXTER6HBaco=&h=864&w=834&sz=215&hl=es-419&start=6&zoom=1&tbnid=jjOROVO9h-vKXM:&tbnh=145&tbnw=140&ei=99eRUY6xKo2K9QTLvYCoDQ&prev=/search%3Fq%3Dphoneutria%2Bfera%26sa%3DN%26hl%3Des-US%26sout%3D1%26tbm%3Disch%26prmd%3Divns&itbs=1&sa=X&ved=0CDYQrQMwBQ Can you see the similarities?, unfortunately the spider might be in a better life today 🙂 Another thing, when you want identifications you should take a picture in front, the under part, and the upper part, as well as some characteristics about behaviour like how they react when you approach. The Phoneutria is a very agressive one.. best wishes, bye.

Hi Miguel, Thanks so much for the comment. This is a seven year old posting and we did not have the ability to post comments when it was originally posted online. We have made an update on What’s That Bug? and your comment is greatly appreciated.

Ah, there is also needed the size and the picture of its face so we can see the eye arrangement, depending on that it could also be pisauridae, but I stay in Ctenidae..

This is a female Cupiennius sp. wandering spider.

Perhaps surprisingly, this ubiquitous large spider of the Mindo area appears to be undescribed to species level.

Although one is indeed best advised to exercise caution in the presence of large ctenids, members of the genus Cupiennius are not known to be dangerously venomous (Barth, 2002). By way of confirmation, my girlfriend, Shannon Bowley, managed to be bitten by a mature female of this Mindo species in 2013 – she felt only mild effects, equivalent to a bee sting.

Thanks for this valuable information.

I’m planning a trip to Ecuador and I’m fearing these spiders. Do they get in houses? Any tips to keep them out, so I can sleep at night?

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Facts About Animals

Brazilian Wandering Spider Facts

Brazilian wandering spider profile.

There are more than 50,000 species of spider, and the vast majority are less dangerous than a honeybee. Almost none are aggressive, and of those with medically significant venom, only a small percentage are capable of causing death. So, on the whole, arachnophobes are just being a bit silly.

But there’s one spider that vindicates all of these fears, and few animals are as globally renowned to be a serious threat to human lives as the Brazilian Wandering Spider .

Brazilian Wandering Spiders are actually 9 species of spider in the same genus ‘Phoneutria’, one of which is found in Central America, with the rest in South America.

Brazilian Wandering Spider Facts Overview

These spiders are called wandering spiders because of instead of spinning a web to wait for food, or occupying a lair, they spend their night wandering in the leaf litter of the jungle floor for prey.

The sensitive hairs on its body help detect vibrations of passing prey, and it will feed on insects, lizards, frogs and any animals as large as itself.

During the day they will hide under logs, rocks, or inside termite mounds and banana plants. They will also sometimes wander into urban areas and homes, where they can come into contact with humans.

Brazilian wandering spiders are aggressive , dangerous and frightening. For once, this is an animal you should be wary of.

The females are larger, around 50% heavier than males, and produce more venom, and this might be a clue as to why their Greek name translates to “ Mudress” . These spiders will often stand and fight and have an intimidating threat display.

The potency of their venom is one of the reasons they’re so dangerous, and their ability to hide away in fruit and shoes explains why most bites are on extremities.

Interesting Brazilian Wandering Spider Facts

1. armed spiders.

In Brazilian, these are sometimes known as armed spiders, on account of their elongated front legs.

They can convey quite a bit of information with these legs, and as wandering spiders, use them to get about the forest, looking for food.

2. Banana Spiders

They’re also sometimes called ‘banana spiders’ on account of their status as a stowaway on popular fruit imported from the tropics.

This is becoming less common as stricter regulations ensure there’s less contamination of fruits, but there’s always a chance your next bunch of bananas will have a family of these spiders living inside it.

3. They have the largest venom glands of any spider

Females produce more venom than males, but both sexes have enormous venom glands. These glands are even more impressive when you consider the size of the spider is significantly less than the largest around.

The venom glands of the Brazilian Wandering Spider are over a centimetre long, and this is all housed inside the bright red chelicerae (mouth parts) which they are quick to display whenever they get upset. 1

4. They’re aggressive

These spiders can grow quite large and have long, brightly-coloured legs. Unlike most spiders, they’re known to stand their ground when threatened and are far quicker to bite than many other species.

They’ll still try to scurry away where possible, and they’re not out to get anybody.

But where most other species will flee, the wandering spiders’ aggression does make it more likely to be involved in incidents.

Most bites are on fingers and toes, a sign that they’re being stepped on or grabbed inadvertently. When the spider feels cornered, it’ll rear up on its back legs and waves its colourful arms around as a warning.

Then it’ll sway side to side, beckoning you to have a go. Anything foolhardy enough to call this bluff gets a wealth of envenomation effects. 2 3

5. They give some men erections

There are ways to accomplish this with fewer side effects, but a bit from a Brazilian wandering spider does come with a certain Viagral quality.

This isn’t as fun as it might sound. Prolonged erections in this manner are likely to harm and destroy muscles and blood vessels in the penis and could cause irreparable damage.

Besides this, the assault on the central nervous system that comes with envenomation by this spider doesn’t sound worth it. 4

6. And some people die

This assault brings with it a whole host of unpleasant symptoms. Seizures, foaming at the mouth, inability to speak, collapse, and a host of other miserable experiences.

Paralysis is possible, as is cardiac shock. Blood vessels can burst in the brain, or anywhere else, and in many cases, this can be enough to kill a person.

This spider has one of the most potent venoms of all, and there are multiple legitimate records of death as a result of bites.

7. But they’re rarely fatal

While the Brazilian wandering spider is potentially one of the most dangerous spiders in the world, there is some evidence to suggest it gives a dry bite, defensively.

This means that despite exceptionally toxic venom, the amount actually injected is less than some of the other contenders, and this is what makes it typically less lethal than the Australian funnel webs.

These spiders are classified as Dangerous Wild Animals and would therefore require a special permit to keep. Bites from wandering spiders are common in South America, but antivenom is often readily available, and they rarely result in death.

In most cases, lethal bites are cases of a very young or very old victim, and few people of healthy age are killed. 5

8. They do invade the UK sometimes

These unquestionably scary spiders show up in supermarkets in the UK on occasion, having hitched a ride on banana shipments.

On more than one occasion they’ve made their way into shoppers’ homes, but it doesn’t appear that there are any cases of them biting people as a result.

These spiders aren’t suited for temperate climates and don’t survive Winter, so there’s no risk of them multiplying.

Brazilian Wandering Spider Fact-File Summary

Scientific classification, fact sources & references.

• PeerJ. (2017), “ Dimensions of venom gland of largest venom glands in all spiders ”, Bio Numbers.
• Dave Clarke (2010), “ Venomous spider found in Waitrose shopping ‘beautiful but aggressive’” , The Guardian.
• “ Phoneutria Perty (Arachnida: Araneae: Ctenidae) ”, UF-IFAS University of Florida
• Kátia R.M. Leite (2012), “ Phoneutria nigriventer spider toxin Tx2-6 causes priapism and death: A histopathological investigation in mice ”, Science Direct.
• “ Brazilian wandering spiders: Bites & other facts ”, Live Science.

Brazilian Wandering Spider

The Brazilian Wandering Spider (Phoneutria fera) is a teardrop-shaped arachnid with a brown coloration. Known for its potent venom, it thrives in both the lush rainforests and human dwellings of Brazil. Its notorious wandering behavior makes it a significant presence in its habitats.

Fascinating Facts about Brazilian Wandering Spider

Here are 3 interesting facts about Brazilian Wandering Spider:

• The Brazilian Wandering Spider is considered the world's most venomous spider by the Guinness World Records.
• They are known as 'wandering' spiders because they roam the jungle floor at night instead of residing in a lair or web.
• Despite their notorious reputation, their bites rarely cause death in humans due to the small amount of venom they inject.

Taxonomy and Classification

Here is the scientific categorization of Brazilian Wandering Spider, providing a glimpse of their position in the biological hierarchy:

Lifecycle and Growth

Brazilian Wandering Spider's life is a journey of transformation - an adventure marked by the following captivating stages:

Egg → Spiderling → Adult

The Brazilian Wandering Spider, primarily found in the rainforest, exhibits a lifecycle that spans both wilderness and human habitats. From egg to adult, it navigates a complex path through dense foliage and human dwellings, adapting to these contrasting environments.

Brazilian Wandering Spider Behaviour and Adaptations

Brazilian Wandering Spiders are known for their nomadic behavior. Instead of building webs to catch prey, they actively hunt at night, using their highly developed senses, particularly vision, to locate and stalk their prey.

These arachnids have adapted to a wide range of habitats, from forests to urban areas. Their potent neurotoxic venom, one of the most powerful among spiders, allows them to incapacitate and consume a variety of prey.

Brazilian Wandering Spider Interaction with the Ecosystem

Now, let's look at how they help maintain the balance in the ecosystem:

• Brazilian Wandering Spiders play a crucial role in controlling the population of their prey, which includes insects and small mammals.
• They serve as a food source for larger animals, contributing to the food chain in their ecosystem.
• Their venom, although dangerous to humans, is studied for medicinal purposes including treatments for erectile dysfunction and pain relief.

Threats to Brazilian Wandering Spider

Despite their popularity and predator status, Brazilian Wandering Spider encounter several threats as well:

• Destruction of natural habitat due to deforestation
• Increased usage of pesticides affecting their food chain
• Climate change potentially disrupting their breeding patterns

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Rabidosa rabida

Geographic range.

Rabidosa rabida is very common and widely distributed. It is often recorded as a wandering spider. It is typically found in east to central Texas and Oklahoma, northward to Nebraska. It has frequently been traced as far east as Maine and as far south as Florida. ( Jackman, 1997 )

• Biogeographic Regions

Rabidosa rabida ismost often found in wooded areas, cotton fields, and buildings. These spiders usually reside among litter, rubbish, in holes, under rocks, and on low foliage in these areas. Some individuals have been found around ponds or in deep burrows with a turret of debris. ( Jackman, 1997 ; Milne and Milne, 1980 ; Parker, 1982 )

• Habitat Regions
• terrestrial
• Terrestrial Biomes
• Other Habitat Features
• agricultural

Physical Description

A typical rabid wolf spider has a dark gray cephalothorax with two light longitudinal stripes extending across the top and a narrow light line on each lateral margin of the thorax. The abdomen has a dark median band, notched on each side in front of the middle of the abdomen, with several pairs of light spots on the rear part of the abdomen. The first pair of legs is often black or dark brown, and the other legs are brown. Females average 16 to 21 mm long, Males are typically much smaller than females, measuring an average of 13 mm in length. ( Comstock and Gertsch, 1965 ; Milne and Milne, 1980 )

• Other Physical Features
• ectothermic
• bilateral symmetry
• Sexual Dimorphism
• female larger
• Average length males, 13 mm; females 21 mm in

Development

Female R. rabida drag their egg mass around, having spun a silken cocoon around the egg mass and attached it to spinnerets. The cocoon darkens from shiny white to dirty brown before the eggs hatch.

Spiderlings ride on their mother's back until they are ready for dispersal. Egg sacs are from 7 to 10 mm in diameter and contain from 168 to 365 eggs. ( Jackman, 1997 ; Milne and Milne, 1980 )

Reproduction

Female R. rabida release a dragline. Males stumble across the line, which leads them to the female. Once courting is over, the male spins a ball of silk and then releases sperm onto the ball. The female attaches the ball and drags it along with her until she is fertilized. ( Rovner, 1991 )

Reproduction in R. rabida is one of the most commonly debated and studied areas of the animal's behavior. Rabid wolf spiders efficiently detect movements. When males and females are in courtship mode, they use a series of displays to interact and breed. R. rabida perform a series inter-bout turns in which one spider turns in a given direction based upon the direction in which the other spider turned previously. Pheromones also play a role in these intricate courting rituals. Scientists have shown that the intensity of the pheromone is directly related to the turning in males, specifically the degree and time of turning.

Spiderlings ride on their mother's back until they are ready for dispersal. Egg sacs are from 7 to 10 mm in diameter and contain from 168 to 365 eggs. ( Jackman, 1997 ; Milne and Milne, 1980 ; Rovner, 1991 )

• Key Reproductive Features
• seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• delayed fertilization
• Breeding season Breeding occurs from late summer to early fall.
• Range number of offspring 168 to 365

The spiderlings hatch and remain on the mother's back until they are ready for dispersal. ( Jackman, 1997 )

• Parental Investment
• provisioning
• pre-weaning/fledging

Lifespan/Longevity

Most rabid wolf spiders live up to around two years, six months of which is sometimes spent on the mother's back. The larger, more fit R. rabida can live beyond two years in stable environments. ( Comstock and Gertsch, 1965 )

• Range lifespan Status: wild 2 (high) years
• Typical lifespan Status: wild 2 (high) years

Because rabid wolf spiders are among the most common spiders in the United States, they have adapted to many types of environments. These spiders are very aggressive towards humans, spiders,other animals and insects. Because of their wandering habits, these spiders are subject to a plethora of interactions between the same and other species. Although harmless to humans, its bite is often feared. ( Milne and Milne, 1980 )

• Key Behaviors
• terricolous

Communication and Perception

Rabid wolf spiders communicate in many different ways. One way is through the release of pheromones. Both males and females lay out a dragline and deposit a chemical attractor on the line. Male wolf spiders intersect these lines and use their palps to follow the line for mating. Another type of communication is web vibrations. This type of communication, known as the substratum-coupled vibration system, is used mainly by males to attract females, but is also used for males to communicate with one another. Essentially, a male "plucks" the web fibers to play a "song". ( Comstock and Gertsch, 1965 ; Milne and Milne, 1980 ; Rovner, 1991 ; Unknown, 1999 )

• Communication Channels
• Other Communication Modes
• Perception Channels

Food Habits

Rabid wolf spiders usually prefer to eat small insects and other invertebrates. They have been known to eat crickets, locusts, ants, grasshoppers and even other spiders. R. rabida is very strong and is not usually intimidated by larger organisms. These spiders are "sit-and-wait" predators. In order to more easily detect visual and vibratory cues from prey, R. rabida must remain motionless. These spiders do not eat solid material, so once they overtake the insect, they usually suck out liquids and nutrients of their prey. ( Jackman, 1997 ; Parker, 1982 ; Rovner, 1989 )

• Primary Diet
• insectivore
• Animal Foods
• terrestrial non-insect arthropods

While Rabidosa rabida is nomadic and moves frequently, it does so in a manner that is inconspicious to larger predators. By staying low in the brush, under litter or ground cover, the spider can move efficiently and most often remains undetected. Wolf spiders get their name from they way they stalk their prey slowly and from a distance, which has been associated with wolves and other wild dogs. ( Parker, 1982 ; Rovner, 1989 )

• Other Wolf Spiders

Ecosystem Roles

Rabidosa rabida has a limited role in th ecosystem. Its main job as a predator is to control the booming insect population. However, as an occasional prey species, it may contribute to feeding other organisms also.

Economic Importance for Humans: Positive

Although it is of little direct benefit to humans, R. rabida is very common among semi-urban and rural areas and is very active in its predation of insects. This can be a big benefit where pests are a problem.

• Positive Impacts
• controls pest population

Economic Importance for Humans: Negative

Rabidosa rabida has little adverse affect on humans outside of being pests. These spiders are not poisonous but have been know to bite unsuspecting victims.

• Negative Impacts
• household pest

Conservation Status

Rabid wolf spiders are not currently endangered or at any prevelant risk of becoming threatened.

• IUCN Red List No special status
• US Federal List No special status
• CITES No special status
• State of Michigan List No special status

Contributors

Nancy Shefferly (editor), Animal Diversity Web.

Justin Scarborough (author), Southwestern University, Stephanie Fabritius (editor), Southwestern University.

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

uses sound to communicate

living in landscapes dominated by human agriculture.

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

an animal that mainly eats meat

uses smells or other chemicals to communicate

a substantial delay (longer than the minimum time required for sperm to travel to the egg) takes place between copulation and fertilization, used to describe female sperm storage.

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

An animal that eats mainly insects or spiders.

having the capacity to move from one place to another.

the area in which the animal is naturally found, the region in which it is endemic.

generally wanders from place to place, usually within a well-defined range.

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

chemicals released into air or water that are detected by and responded to by other animals of the same species

breeding is confined to a particular season

reproduction that includes combining the genetic contribution of two individuals, a male and a female

living in residential areas on the outskirts of large cities or towns.

uses touch to communicate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

Living on the ground.

living in cities and large towns, landscapes dominated by human structures and activity.

movements of a hard surface that are produced by animals as signals to others

uses sight to communicate

young are relatively well-developed when born

Comstock, J., W. Gertsch. 1965. The Spider Book . Ithaca, New York: Comstock Publishing Company, Inc..

Jackman, J. 1997. A Field Guide to Common Texas Insects . Houston: Gulf Publishing Company.

Milne, L., M. Milne. 1980. The Audubon Society Field Guide to North American Insects and Spiders . New York: Chanticleer Press, Inc..

Parker, S. 1982. Synopsis and Classification of Living Organisms Volume 2 . McGraw-Hill Book Company.

Rovner, J. 1991. Turning behavior during pheromone-stimulated courtship in wolf spiders. Animal Behaviour , 42: 1015-1016.

Rovner, J. 1989. Wolf Spiders lack mirror-image responsiveness seen in jumping spiders. Animal Behaviour , 38: 526-533.

Unknown, 1999. "Introduction to Ethology" (On-line). Accessed Oct. 3, 2001 at http://cas.bellarmine.edu/tietjen/Ethology/introduction_to_ethology.htm .

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Classification.

• Kingdom Animalia animals Animalia: information (1) Animalia: pictures (22861) Animalia: specimens (7109) Animalia: sounds (722) Animalia: maps (42)
• Class Arachnida Arachnida: information (1) Arachnida: pictures (250) Arachnida: specimens (1)
• Order Araneae Araneae: pictures (221)
• Family Lycosidae Lycosidae: pictures (25)
• Genus Rabidosa
• Species Rabidosa rabida Rabidosa rabida: information (1)

To cite this page: Scarborough, J. 2002. "Rabidosa rabida" (On-line), Animal Diversity Web. Accessed June 15, 2024 at https://animaldiversity.org/accounts/Rabidosa_rabida/

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Brazilian wandering spider | bite,Size, Habitat, & Facts

Brazilian wandering spider.

brazilian wandering spider size

Their body length ranges from 17 to 48 mm (43⁄64 to 1+57⁄64 in). Phoneutria are impressive spiders reaching body sizes up to 3.5 centimeters and leg spans up to 15 centimeters. They are nocturnal, hunting at night, and hiding in dark places during the day.

Wandering spider bite

Along with other members of the genus, they are often referred to as Brazilian wandering spiders. Its bite can cause severe symptoms, including increased pulse, blood pressure, and respiratory rate; extraordinary pain; penile erection that lasts for several hours; and, in several documented cases, death.

Phoneutria spp.  is actually a genus with five known similar species whose members are highly venomous. They include some of the relatively few species of spiders that present a threat to human beings. The Brazilian Wandering Spider (Phoneutria fera) can grow to have a leg span of up to 4-5 inches.

Wandering spider, (family Ctenidae), any member of the family Ctenidae (order Araneida), a small group of large spiders of mainly tropical and subtropical regions, commonly found on foliage and on the ground.

The Brazilian wandering spiders, Phoneutria fera and P. nigriventer, are sometimes also referred to as banana spiders because they are frequently found on banana leaves. They have an aggressive defense posture, in which they raise their front legs straight up into the air. Phoneutria are venomous, and their venom is toxic to the nervous system, causing symptoms such as salivation, irregular heartbeat, and prolonged painful erections (priapism) in men. Scientists are investigating the venom of P. nigriventer as a possible treatment for erectile dysfunction.

These spiders are notorious both due to their toxic venom, and because they are not reluctant to attack people who appear threatening.

Of the five species known, P. nigriventer and P. fera most frequently receive mention in mass-media publications. P.nigriventer species are responsible for most cases of venom intoxication in Brazil because this species is commonly found in highly populated areas of Brazil, namely the South-eastern states: São Paulo, Minas Gerais, Rio de Janeiro and Espírito Santo.The P. fera is native to the northern portion of South America, especially the Brazilian Amazônia, Venezuela and French Guiana.

Brazilian wandering spider BITES AND VENOMB

　　razilian wandering spiders’ venom is a complex cocktail of toxins, proteins and peptides, according to the Natural History Museum in Karlsruhe, Germany. The venom affects ion channels and chemical receptors in victims’ neuromuscular systems.

　　After a human is bitten by one of these spiders, he or she may experience initial symptoms such as severe burning pain at the site of the bite, sweating and goosebumps, Sewlal said. Within 30 minutes, symptoms become systemic and include high or low blood pressure, fast or a slow heart rate, nausea, abdominal cramping, hypothermia, vertigo, blurred vision, convulsions and excessive sweating associated with shock. People who are bitten by a Brazilian wandering spider should seek medical attention immediately.

Recent studies suggest that these spiders only inject venom in approximately one-third of their bites and may only inject a small amount in another third. However, research in this area is hindered by the difficulty of identifying particular subspecies. Thus the effects of the bites from these spiders are hard to predict when based on sketchy information or if the spider has not been identified definitively. 

Bites from these spiders may result in only a couple of painful pinpricks to full-blown envenomation. In either case, people bitten by a Phoneutria or any Ctenid should seek immediate emergency treatment as the venom is possibly life threatening.

he Phoneutria fera and nigriventer  are the two most commonly implicated as the most virulent of the Phoneutria spiders. The Phoneutria not only has a potent neurotoxin, but is reported to have one of the most excruciatingly painful envenomations of all spiders due to its high concentration of serotonin.  

Brazilian Wandering Spiders are extremely fast, extremely venomous, and extremely aggressive and are ranked among the most venomous spiders known to man. In fact, the Brazilian Wandering Spider is the most venomous spider in the New World! In South America, these true spiders are commonly encountered in peoples’ homes, supposedly hiding in peoples’ shoes, hats, and other clothes. It does not remain on a web, rather, it wanders the forest floor, which is how it got its name.

The Brazilian Wandering Spider has another name – the  Banana Spider  and it was given this name  because there have been cases where these spiders unintentionally appeared on banana boats heading for the United States.

​　　Brazilian Wandering Spider: One Of The World’s Most Venomous Spiders May Be Lurking In Your Bananas

　　Meet the Brazilian wandering spiders in the genus Phoneutria, also referred to as the armed spiders or the banana spiders. The members of this group have one of the most dangerous bites of any spider species on Earth and they have been classified as the world’s most venomous spider many times.

　　What Are The Effects Of A Brazilian Wandering Spider Bite?

　　Brazilian wandering spiders often make the news because of the unusual symptoms caused to humans after being bitten by one.

　　A 2023 study in Frontiers In Molecular Biosciences suggested there were around 4,000 cases of people being bitten by Phoneutria nigriventer in Brazil each year. Their venom affects the nervous system, causing double vision, salvation, irregular heartbeat – and even prolonged painful erections, known as priapism. In fact, because of this, their venom is being explored as a possible treatment for erectile dysfunction conditions.

　　Can A Brazilian Wandering Spider Bite Kill You?

　　The neurotoxin PhTx3 is to blame for these symptoms, and according to the Independent, a wandering spider bite can reportedly be fatal in as little as 60 minutes. However, an effective anti-venom is usually enough to save those affected. A study into Phoneutria boliviensis in 2019 suggested that the species had adapted its venom to catch vertebrates as opposed to lizards and amphibians, which might explain why the venom is so toxic to humans.

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• Spider Facts

Brazilian Wandering Spider: Size, Bite, Diet and Other Facts 

The Brazilian Wandering Spider is a venomous arachnid with a fearsome reputation. This South American rainforest dweller packs a powerful punch, but don’t let its nickname “banana spider” fool you – they’re active hunters, not web-spinners. Despite their size and venom, bites are uncommon as they’re typically shy.

The Brazilian Wandering Spider has garnered significant attention due to its potent venom, which makes it one of the world’s most venomous spiders. Understanding its biology and behavior is crucial for both scientific research and public safety.

Scientific classification

The Brazilian Wandering Spider belongs to the family Ctenidae within the order Araneae. Its scientific classification is as follows:

• Kingdom: Animalia
• Phylum: Arthropoda
• Class: Arachnida
• Order: Araneae
• Family: Ctenidae
• Genus: Phoneutria

The Brazilian Wandering Spider goes by various common names, including “armed spider,” “banana spider,” and “wandering spider.” Synonyms for this species may include Ctenus , which was formerly used for some Phoneutria species.

Distribution and habitat

Distribution:

• South American:  Found throughout most of South America east of the Andes mountains, including countries like Brazil (their namesake), Argentina, Paraguay, and up into northern regions.
• Central American Touch:  A few species even reach southern Central America.
• Rainforest Dwellers:  Primarily found in the lush rainforests of South America.
• Not Picky Places:  They can also adapt to other habitats like the Atlantic Forest and even some urban areas.
• Daytime Hideouts:  While they wander at night, they seek shelter during the day in places like termite mounds, under rocks, or even (unintentionally) in bananas!

Physical Characteristics

 size and weight.

The Brazilian wandering spider is a creepy crawly giant. Their bodies can grow up to 2 inches (5 centimeters) long, but that’s not the scary part. Their legs can span a whopping 7 inches (18 cm), making them look even bigger. They are one of the biggest true spiders by body weight and size.

Despite their impressive leg span, Brazilian wandering spiders are relatively light. They only weigh around 6 grams, which is about the same as two pennies. While they might look imposing, they’re not the heaviest arachnids around.

Coloration and markings

These spiders exhibit a range of colors, including brown, black, and sometimes reddish hues. They often have distinctive markings on their bodies, which can vary between species. These markings may include stripes or patterns that serve as a key identification feature.

Notable features

One of the most notable features of the Brazilian Wandering Spider is its elongated, robust body and long, agile legs. They have sharp fangs, which they use to inject venom into their prey or in self-defense.

Sexual dimorphism

Sexual dimorphism is evident in this species. Females are larger and bulkier than males, while males have longer, more slender legs. Additionally, males possess specialized structures known as pedipalps, which are used during mating.

In the following sections of this article, we will delve deeper into the behavior, venom, and ecological role of the Brazilian Wandering Spider, shedding light on why this species has both fascinated and instilled fear in those who encounter it.

 Behavior and Ecology

 Nocturnal habits

Brazilian Wandering Spiders are primarily nocturnal creatures. They are most active during the night, venturing out of their daytime hiding places to hunt for prey and engage in mating activities. Their nighttime activity allows them to avoid predators and reduce the risk of desiccation in the hot tropical sun.

Hunting and feeding behavior

These spiders are agile hunters and primarily feed on insects, small vertebrates, and other arachnids. They do not build webs to capture prey but instead rely on their excellent senses, including acute vision and touch, to locate and stalk their victims. They often wander in search of food and are known for their swift and lethal strikes. Once they subdue their prey, they inject venom to immobilize it before feeding.

Brazilian Wandering Spiders (Phoneutria) are active hunters and have distinctive feeding behaviors. Here’s an overview of their feeding habits:

• Active Predators: Brazilian Wandering Spiders are not web-builders like many other spider species. Instead, they are active predators. They actively roam their environment in search of prey rather than waiting for insects to stumble into a web.
• Hunting Strategy: When hunting, these spiders use their excellent senses, including acute vision and touch, to locate potential prey. They are known for their agility and speed, which they use to stalk and capture their victims. They have sharp fangs, which they use to deliver a venomous bite to immobilize their prey.
• Diet: Their diet consists primarily of insects and other arthropods, but they are opportunistic feeders and may consume a variety of small creatures, including small vertebrates such as frogs and lizards when the opportunity arises.
• Venom Use: Brazilian Wandering Spiders inject venom into their prey to immobilize and partially digest it. Their venom contains neurotoxins that affect the nervous system of their victims. Once the prey is incapacitated, the spider can feed on it at its leisure.
• Feeding Process: After subduing their prey with a venomous bite, the spider uses its chelicerae (fangs) to break down the prey’s tissues. The venom also helps in predigestion, turning the prey’s insides into a semi-liquid form that the spider can ingest. They can consume both the internal fluids and solid parts of their prey.
• Frequency of Feeding: The frequency of feeding can vary depending on factors such as the availability of prey and the spider’s size. Generally, they need to feed periodically to sustain their energy and growth. Spiderlings may require more frequent meals to support their rapid growth, while adults can go longer periods between meals.

Overall, the Brazilian Wandering Spider’s feeding strategy is well-suited for their active and wandering lifestyle, allowing them to efficiently capture and consume a variety of prey in their natural habitat.

Role in the ecosystem

The Brazilian Wandering Spider plays a vital role in controlling insect populations within its habitat. By preying on a variety of insects and other small creatures, they help maintain ecological balance. Additionally, their presence in the rainforest ecosystem contributes to the overall biodiversity and food web.

Mating and reproduction

Mating in Brazilian Wandering Spiders is a complex and potentially dangerous process. Male spiders must carefully approach and court a receptive female to avoid being mistaken for prey. They use specialized pedipalps to transfer sperm to the female’s reproductive organs. After successful mating, females lay egg sacs containing hundreds of eggs. They guard these sacs and ensure the survival of their offspring until they hatch.

 Lifespan and growth

The lifespan of Brazilian Wandering Spiders varies between males and females. Males generally have a shorter lifespan, typically living for a few months to a year after reaching maturity. Females, on the other hand, can live for several years. The growth of these spiders involves a series of molts, during which they shed their exoskeletons to accommodate their increasing size. Molting is a vulnerable period in their lives as their new exoskeleton is initially soft and requires time to harden.

Venom and Envenomation

Composition of venom.

The venom of Brazilian Wandering Spiders is a complex mixture of neurotoxins, cytotoxins, and other enzymes. One of the most significant components is a neurotoxin called PhTx3, which targets the nervous system of their prey.

Toxicity and effects on humans

The venom of these spiders is highly potent and can be lethal to their prey. In humans, envenomation can cause a range of symptoms, including intense pain, muscle cramps, fever, nausea, and in severe cases, paralysis and death. It’s important to note that while their venom is potent, actual fatalities from Brazilian Wandering Spider bites are rare due to the availability of medical treatment.

First aid and medical treatment

In the event of a Brazilian Wandering Spider bite, immediate medical attention is crucial. First aid measures may include cleaning the wound and applying ice to reduce pain and swelling. However, the primary treatment involves antivenom, which can counteract the effects of the spider’s venom.

Cases of envenomation and fatalities

Although fatalities from Brazilian Wandering Spider bites are uncommon, there have been documented cases of severe envenomation, especially in regions where medical treatment is not readily available. These spiders are generally non-aggressive and will bite humans only in self-defense when provoked, or if they feel cornered.

Understanding the behavior, ecology, and venomous nature of the Brazilian Wandering Spider is crucial for both scientific research and public awareness, helping to minimize the risk of envenomation and promote coexistence with this remarkable but potentially dangerous arachnid.

Brazilian wandering spider life cycle

The Brazilian wandering spider has a fascinating life cycle that revolves around hunting and motherhood. Here’s a breakdown:

• Egg Haven:  After mating, the female lays hundreds, sometimes even a thousand, eggs in a silken sac. This becomes their protected nursery.
• Tiny Terrors:  Hatching from the eggs emerge translucent spiderlings called larvae.
• Nymph Stage:  The larvae molt a few times, transforming into nymphs. Think of them as mini-adults but without the ability to reproduce yet.
• Shedding for Size:  As nymphs grow, they undergo multiple molts, shedding their outer shell to accommodate their larger bodies.
• Ready to Roam:  After the final molt, the spider emerges as a full-fledged adult, complete with reproductive organs. Now, they can join the wandering lifestyle and continue the cycle.

The life cycle begins when a female Brazilian Wandering Spider lays her eggs. She typically creates an egg sac made of silk and deposits it in a concealed location, such as a tree hollow or leaf litter. Inside the sac, she may lay hundreds of eggs. The female guards the egg sac and ensures its protection until the spiderlings hatch. The duration of the egg stage varies depending on environmental conditions but generally lasts for a few weeks.

Spiderling Stage

After the incubation period, spiderlings (young spiders) emerge from the egg sac. They are extremely vulnerable at this stage and rely on their mother’s protection and guidance. Spiderlings are miniature versions of adult spiders but lack the full coloration and size. They disperse from the nest once they have molted and are capable of hunting on their own. During this stage, they grow rapidly by molting, shedding their exoskeletons to accommodate their increasing size.

Juvenile Stage

As spiderlings continue to molt and grow, they progress into the juvenile stage. During this phase, their coloration becomes more distinct, and they start to develop the characteristic features of adult Brazilian Wandering Spiders. They become increasingly independent and begin to exhibit hunting behaviors. The duration of the juvenile stage can vary but often lasts several months.

Sub-Adult Stage

The sub-adult stage is an intermediate phase between juvenile and adult. At this point, the spiders are closer in size and appearance to adults but have not yet reached sexual maturity. They continue to molt, with the frequency of molting gradually decreasing as they approach adulthood. Sub-adult spiders may exhibit more territorial behaviors as they compete for resources and prepare for eventual mating.

Adult Stage

Upon reaching sexual maturity, Brazilian Wandering Spiders enter the adult stage. This is when they are fully developed and capable of reproduction. Females are larger and bulkier than males, and males possess specialized structures called pedipalps, which they use during mating. Adult spiders engage in mating activities, and females lay eggs to continue the life cycle. Adult Brazilian Wandering Spiders can live for several years, with females typically having longer lifespans than males.

Understanding the life cycle of these spiders is essential for studying their behavior, reproductive biology, and population dynamics. It also provides insights into their adaptation strategies in the complex ecosystems of South and Central America.

Brazilian Wandering Spider Bite

Brazilian Wandering Spiders are known for their potent venom and, occasionally, their bites on humans. While bites are relatively rare due to the spider’s non-aggressive nature, understanding the consequences of a bite is crucial for public safety.

Studying Brazilian Wandering Spider bites is of great interest for several reasons. It helps healthcare professionals provide appropriate medical treatment, raises awareness among communities in spider habitats, and contributes to our understanding of venomous arachnid envenomations.

The venom of Brazilian Wandering Spiders is a complex mixture of neurotoxins, cytotoxins, and enzymes. It contains various components, including PhTx3, which is a potent neurotoxin affecting the nervous system.

Brazilian Wandering Spider bites can have a range of effects on the human body, including intense pain, muscle cramps, fever, nausea, and in severe cases, paralysis. The severity of the symptoms depends on factors such as the amount of venom injected and the individual’s sensitivity to the venom. There are several types of spider bites .

Symptoms of a Brazilian Wandering Spider Bite

Local symptoms

• Intense pain
• Itching or burning sensation
• Formation of blisters or lesions

Systemic symptoms

• Muscle cramps and spasms
• Abdominal pain
• Nausea and vomiting
• Elevated heart rate
• Hypertension (high blood pressure)
• Respiratory distress

Severity and variations

The severity of Brazilian Wandering Spider bite symptoms can vary widely. In some cases, symptoms may be mild and resolve on their own, while in severe envenomations, life-threatening complications can occur. Individual reactions to the venom can also vary, making it challenging to predict the exact outcome of a bite.

First Aid and Immediate Response

Steps to take after a bite

Immediate response to a Brazilian Wandering Spider bite should include:

• – Washing the bite area with soap and water.
• – Applying a clean, cool compress to reduce pain and swelling.
• – Immobilizing the affected limb or area.
• – Keeping the bite victim calm to prevent an elevated heart rate.

Do’s and don’ts in case of a bite

• – Seek medical attention promptly.
• – Take note of the spider’s appearance (if possible) to aid identification.
• – Keep the bite victim still and calm to reduce the spread of venom.
• – Do not try to suck out venom or make incisions at the bite site.
• – Avoid applying tourniquets.
• – Don’t use ice directly on the skin as it can worsen tissue damage.

Seeking medical attention

Medical attention is essential after a Brazilian Wandering Spider bite, even if symptoms appear mild initially. Antivenom is available and can be administered to counteract the effects of the venom. Medical professionals can also manage symptoms and monitor for potential complications.

Complications and Long-Term Effects

Potential complications

Complications from Brazilian Wandering Spider bites can include:

• – Severe muscle spasms
• – Respiratory distress
• – Cardiovascular issues
• – Kidney failure (rare)
• – Allergic reactions to antivenom

Long-term consequences

Long-term consequences of a bite can vary depending on the severity and medical treatment received. Some individuals may experience lingering pain, muscle weakness, or psychological trauma following a severe envenomation.

Recovery and rehabilitation

Recovery from a Brazilian Wandering Spider bite typically involves medical treatment, rehabilitation for muscle and nerve damage, and psychological support for individuals affected by the experience. Rehabilitation may include physical therapy to regain muscle strength and function. Prompt medical attention and appropriate care are crucial for minimizing long-term effects and complications.

Facts of Brazilian Wanding Spider

Here are 10 creepy crawly facts about the Brazilian Wandering Spider:

• Big and Hairy:  These spiders are giants! Their bodies can grow up to 2 inches (5 centimeters) long, with a leg span of up to 7 inches (18 cm). They are covered in hairs, making them appear even bigger.
• Wanderlust:  They are aptly named – Brazilian wandering spiders don’t spin webs. Instead, they wander the forest floor at night in search of prey.
• Venomous Bite:  Their venom is considered one of the most potent among spiders. A bite can cause severe pain, swelling, sweating, nausea, and even priapism in males. Thankfully, bites are rare as they are typically shy and defensive.
• Not So Fond of Bananas:  While sometimes called ‘banana spiders,’ they are not typically found in bananas. They might, however, take shelter in them during transport, which is how they might end up in a faraway land.
• Rainforest Resident:  These spiders are native to the rainforests of South America, particularly in Brazil.
• Fearsome Feasters:  They’re active hunters and will eat almost anything they can overpower, including insects, lizards, frogs, and even small rodents.
• Mom’s the Word:  Female Brazilian wandering spiders are dedicated mothers. They lay hundreds of eggs in a silken sac and fiercely guard them until they hatch.
• Multiple Molts:  Like all spiders, Brazilian wandering spiders grow through molting. They shed their exoskeleton multiple times as they grow into adults.
• Mating Dance:  Male Brazilian wandering spiders perform a elaborate mating dance to attract a female.
• Medicinal Potential:  Despite their scary reputation, the venom of the Brazilian wandering spider is being studied for its potential use in treating erectile dysfunction.

What happens if a Brazilian Wandering Spider bites a man?

A Brazilian Wandering Spider bite on a man can cause a range of symptoms, some severe:

• Pain:  The bite is known for causing intense, localized pain at the site.
• Autonomic effects:  Sweating, nausea, and increased heart rate are common.
• Priapism:  In some cases, males may experience a prolonged and painful erection (priapism). This is due to a component in the venom.
• Muscle paralysis:  Severe bites can lead to muscle paralysis, which can affect breathing in rare cases.

However, it’s important to remember:

• Bites are uncommon as these spiders are typically shy and defensive.
• Antivenom is available and effective in treating bites.

If bitten, seek medical attention immediately. Early treatment can help prevent complications and ensure a full recovery.

How poisonous is a Brazilian Wandering Spider?

Brazilian Wandering Spider packs a nasty venomous punch, considered one of the strongest among spiders. Bites are rare though, as they’re shy and prefer to escape trouble.

What is the world’s deadliest spider?

The term “deadliest” can be subjective and depends on how one defines it (e.g., based on venom potency or human fatalities). However, the Brazilian Wandering Spider (Phoneutria) is often considered one of the most venomous spiders in the world. Another spider often mentioned in discussions of venom toxicity is the Sydney Funnel-web Spider (Atrax robustus and Atrax formosus), found in Australia. These spiders are known for their potent venom and have caused fatalities in the past.

FAQ about Brazilian Wandering Spider

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Brazilian Wandering Spider size: how big do they get?

As an avid arachnid enthusiast, my fascination with these eight-legged creatures knows no bounds. There’s something utterly captivating about their intricate web-weaving capabilities, their exceptional survival strategies, and of course, their range of sizes and appearances. But amongst this vast collection of species, one has particularly piqued my interest – the Brazilian Wandering Spider.

Arguably one of the most notorious names in the world of arachnids, the Brazilian Wandering Spider, holds a firm position at the pinnacle of spider folklore. Their reputation extends far beyond their native tropical South American rainforests, captivating the minds of arachnologists and laymen alike around the globe.

What sets this spider apart in the arachnid world? It’s not just its venomous nature – it’s also its astonishing size. The dimensions of the Brazilian Wandering Spider are a spectacle in themselves.

How big are Brazilian Wandering Spiders?

Picture this: a spider so large that it could comfortably cover an average dinner plate. That’s right – the Brazilian Wandering Spider can grow to an impressive leg span of up to 7 inches , or approximately 18 cm, with females tending to be larger than the males.

To put this into perspective, that’s around half the size of an average adult human’s face! The body length of these spiders can reach up to 2 inches, or around 5 cm. This considerable size, coupled with their highly potent venom, makes them a formidable presence in their habitats.

But as an arachnid hobbyist, the allure of the Brazilian Wandering Spider’s size lies not in its potential threat, but in the fascinating evolutionary adaptations that have allowed it to grow to such an impressive scale.

The advantage of large size for a cursorial hunter

From an evolutionary standpoint, the Brazilian Wandering Spider’s significant size offers multiple advantages. For starters, their considerable size allows them to subdue and consume a larger variety of prey, including insects, other spiders, and sometimes even small amphibians and reptiles. This dietary diversity is a testament to their adaptability and survival prowess.

However, the size of these spiders is not solely an indicator of their hunting prowess. It also reveals a fascinating aspect of their biology. The Brazilian Wandering Spider, unlike some smaller spider species, does not weave a web to capture its prey. Instead, as their name suggests, they wander in search of food, relying on their size and strength to overpower their prey. This is called cursorial hunting .

Their size also plays a crucial role in their mating rituals. Male Brazilian Wandering Spiders, despite being smaller than their female counterparts, engage in a daring dance of danger during mating. They utilize their size and strength to lift the larger female’s body to prevent her from eating him – a gruesome but prevalent behavior known as sexual cannibalism in the arachnid world.

Size relates to the biology of the Wandering Spider

The Brazilian Wandering Spider’s size, therefore, is much more than just an intimidating factor. It’s a key to understanding their hunting methods, their mating rituals, and their overall survival strategy. Each inch adds to the mystique of these extraordinary creatures and deepens our understanding of the diverse world of arachnids.

The Brazilian Wandering Spider is undeniably a creature of fascination. From its substantial size to its potent venom, it’s a spider that demands respect. Whether you’re an arachnid hobbyist like me, or just someone intrigued by the wonders of the natural world, the Brazilian Wandering Spider offers a fascinating insight into the awe-inspiring world of arachnids.

Final thoughts…

In conclusion, the world of spiders is as vast and varied as the creatures themselves. The Brazilian Wandering Spider, with its impressive size, offers a fascinating window into this world. It’s a testament to the incredible diversity of life on Earth and a reminder of the intricate balance that governs our ecosystems.

My fascination with spiders continues to grow, much like the impressive size of the Brazilian Wandering Spider. And while their size may be a source of fear for some, for me, it only fuels my passion and curiosity about these fascinating creatures. After all, understanding is the first step to appreciation, and these giant spiders deserve nothing less.

Whether you’re a fellow arachnid enthusiast or just passing by, I hope this deep-dive into the size of the Brazilian Wandering Spider has sparked your curiosity. So the next time you hear about this giant spider, remember, there’s more to its size than meets the eye!

If you’d like to learn more about these spiders, check out my article on Brazilian Wandering Spider facts .

FAQ related to Brazilian Wandering Spider Size

How bad is a brazilian wandering spider bite.

A Brazilian Wandering Spider bite is considered a medical emergency. If you have a suspected or confirmed bite, your first move should be to contact the emergency services. Upon reaching you, they will determine whether to administer antivenom, and how to proceed with treatment. Fortunately, deaths are very rare, and the antivenom is widely available in South America.

Is a banana spider the same as a Brazilian wandering spider?

The common name of “Banana Spider” is used for a few species, not just the Brazilian Wandering Spider. For example, the Golden Silk Orb Weaver is often referred to as a banana spider, despite being completely unrelated. If you wish to find out if a spider is venomous, always rely on its scientific, or binomial name, rather than common names.

Where do Brazilian wandering spiders hide?

Brazilian Wandering Spiders are nocturnal hunters, and generally prefer to shy away from daylight. This means they often hide in the shadiest places they can find, either indoors or outdoors. For example, under a log or in leaf litter would be a perfect place outdoors. Indoors, they will try to hid behind or under furniture, or in dark corners.

What is the world’s biggest Brazilian wandering spider?

There are around 40 species of Wandering Spider, but the largest, and most infamous are those that we call the Brazilian Wandering Spider. This name is in fact commonly ascribed to two species: Phoneutria nigriventer and Phoneutria fera. Both of these spiders can reach at least 6 inches (15cm) in legspan.

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Brazilian Wandering Spider: Care, Food, Habitat & Preventions

Mike Wallace

Have you ever heard of or do you know what a  Brazilian wandering spider is ? It is a big venomous spider from places like Central and South America, and people sometimes call it the  banana spider . Why? Well, we are about to find out!

Table of Contents

These wandering spiders are aggressive hunters who go out on the hunt at night. Their meals include both invertebrates (like insects) and vertebrates (creatures with a backbone, like small animals).

These spiders are super dangerous because their venom is like a powerful potion that can make people really sick or even worse. They usually hang out in tropical rainforests and even in cities, hiding in banana plants. 

So, let’s get more information about the world of this sneaky spider to learn the details about its looks, eating habits, where it lives, the venom it carries, and find out if it is genuinely risky. Ready to explore? Keep reading!

Brazilian Wandering Spider Description:

Scientific name and family:.

In Brazil, they are sometimes known as “ armed spiders ” (armadeiras), and they share the name “ banana spiders ” with a few other spiders. They have different names, but they are all talking about the same interesting spider!

The Brazilian wandering spider, scientifically known as  Phoneutria , Maximilian Perty kickstarted the Phoneutria genus in 1833. The name comes from the Greek word φονεύτρια , which means “murderess” and falls under the Animalia kingdom, Arthropoda phylum, and Arachnida class.

Within Arachnida, it is classified in the order Araneae, infraorder Araneomorphae, and Ctenidae family. The genus Phoneutria, described by Perty in 1833, includes the type species  Phoneutria fera .

This classification helps us understand where these spiders fit into the larger picture of living organisms.

The following 9 species are accepted by The  World Spider Catalog :

• Phoneutria bahiensis
• Phoneutria boliviensis
• Phoneutria eickstedtae
• Phoneutria fera
• Phoneutria keyserlingi
• Phoneutria nigriventer
• Phoneutria pertyi
• Phoneutria reidyi
• Phoneutria depilata

What do Brazilian Wandering Spider look like?

Size range:.

The spiders in the Phoneutria group can get pretty big in size. Their legs can stretch out to be 13 to 18 centimeters (5 to 7 inches) wide, and their bodies can have a range between 17 to 48 millimeters (a little more than half an inch to almost 2 inches) long.

The female Brazilian spiders can get pretty big, reaching up to 15 centimeters (5.9 inches) in length. On the other hand, the males are smaller, usually measuring around 7 centimeters (2.8 inches). They usually weigh up to 0.21 ounces.

They have long, slender legs, and even though some other spiders with different names might have longer legs, the Phoneutria spiders are champions when it comes to having the longest bodies and being the heaviest in their spider gang.

The spider’s body has two main parts. The first is the prosoma, kind of like its “head,” where you will find all eight legs, eyes, fangs (chelicera), and little multitasking arms (pedipalps).

The second part is the opisthosoma, holding the spinnerets for making silk, the back end opening (anal opening), “the lungs,” the heart, and the important bits for making baby spiders (reproductive organs).

So, the prosoma is like the front control center, and the opisthosoma is like the back office, handling things like silk-making and baby-making.

Brazilian spiders come in different colors, with most being hairy and shades of brown and gray. Some species may have lightly colored spots on their abdomen.

A distinctive feature of many species is the presence of bands of black and yellow or white on the underside of their two front legs.

Identification:

To identify a spider from the Phoneutria group, look for a dense brush of fine hairs on their leg parts. They might seem like other spiders, especially  Cupiennius , but here is how you can differentiate: 

• Phoneutria often have a dark line on the front of their palps and a thin black line on top of their head. 
• Check underneath, too; their legs usually have dark parts and light joints. Sometimes, the belly has black dots or is reddish. 
• Usually it has been observed that when they are upset, they do a cool defensive move like lifting their front legs high with a distinctive pattern. So, if you see a spider doing that dance, it is probably a Phoneutria!

Brazilian Wandering Spiders live all over the Americas, from Costa Rica to northern Argentina. They are like the residents of the jungle, chilling in forests east of the Andes in countries like Colombia, Venezuela, Ecuador, Peru, Bolivia, Brazil, Paraguay, and the Guianas.

Some, like P. reidyi, P. boliviensis, and P. fera, love the Amazon rainforest, while others prefer the Atlantic Forest in Argentina, Paraguay, and Brazil.

They have also made themselves at home in the Cerrado savanna. But if you head to northeastern Brazil, they are not around. These spiders have even taken trips to Chile and Uruguay.

Why are they called Banana Spiders?

These spiders are linked with bananas. Richard S. Vetter, a researcher at the University of California, found that these powerful spiders sometimes end up in North America and Europe by accident, hitching a ride in banana shipments.

But it is often a case of mistaken identity. Only a few Phoneutria species have been found in banana shipments, and sometimes, other spiders get the blame due to misidentification. 

What They Like to Eat or Hunt?

Their food includes flies, beetles, butterflies, moths, grasshoppers, locusts, and crickets. Occasionally, they might even feast on small creatures like amphibians, reptiles, or mice. All these diet or food findings tell us about how diversified eating habits these fascinating spiders have.

Mating and Lifecycle:

Like most spiders, the female spiders are bigger than the males. When the male spider wants to be friends, they do a little dance (vibrating his pedipalps and specialized sensory appendages) to signal his intentions to impress the female, but it is a cautious approach.

The behavior of the female can be choosy, and she might say no to a few before picking the right one. 

After the dance, sometimes, the females decide to attack them, or if she is interested, she can store the male’s baby-making material in a special place until she is ready to use it.

Then, she lays a bunch of eggs, up to 1,000 at a time, and keeps them safe in a silk egg sac. Sadly, after laying her eggs, the mom spider says goodbye. It is her way of making sure the new spiders are ready to explore the world on their own.

The lifespan of the banana spider (Phoneutria nigriventer) differs for males and females. Females usually live for 6 to 8 weeks after reaching maturity, while males have a shorter lifespan of 2 to 3 weeks after their last molt. 

Certain mammals, like coatis (Procyonidae, which includes raccoons) and other small insectivores, birds are potential predators of large wandering spiders.

These spiders got their name as wandering spiders because of the fact that they are not into web building. Instead, they stroll around the forest floor at night(nocturnal), searching for dinner.

Brazilian Wandering Spiders are active hunters and use both ambush tactics and direct attacks to catch their prey. During the day, they prefer cozy spots like under logs or in crevices, only emerging at night for their hunting adventures. These spiders do not build nests like other spider species.

While wandering spiders are not naturally aggressive towards humans, they won’t hesitate to bite if they feel cornered or threatened. Most bites happen when a spider accidentally gets trapped in clothing or bedding. 

Bite and Venom:

The bite of the armed spider is the most dangerous in the world as the venom it carries can be harmful to humans.

The danger is not just about how strong the venom is; it is also about factors like the spider’s likelihood to bite and how close it is to where people live.

These spiders often hide in houses, clothes, and other dark places during the day, making accidental bites more likely. 

While their fangs are adapted for small prey, some experts think they might give a “dry” bite in defense to save venom. Studies suggest that not all bites inject venom, and serious cases requiring antivenom are rare.

However, there have been confirmed cases of death, with symptoms appearing quickly, including:

• Severe pain
• Breathing difficulties
• Increased heart rate and blood pressure
• In severe cases, paralysis and death

The severity can depend on the spider’s sex, with females generally more dangerous. The spiders produce less venom in colder months, and a small amount can be potent enough to harm.

Fortunately, bites from Brazilian spiders are rare, and when they do occur, the exposure to the toxins is generally mild, as explained by Vetter.

Also Read: What is a Huntsman Spider? (Heteropodidae) – The Ultimate Guide

Banana Spider’s Facts:

Below are essential details about Brazilian wandering spiders:

• They hold the title for the world’s largest spiders , boasting leg spans reaching up to 15 centimeters (6 inches).
• Their venom packs a powerful punch, capable of inducing severe pain, paralysis, and, in extreme cases, fatal outcomes for humans.
• Despite their intimidating reputation, they are generally non-aggressive and resort to biting only when provoked.
• These spiders inhabit tropical rainforests and urban areas across Central and South America.
• In case someone has been bitten by this spider, he/she needs quick medical treatment to control the effects timely.

Treatment and Preventive Measures:

If bitten by a wandering spider or armed spiders, prompt medical attention is crucial. There is an antivenom for the spider’s venom, but its effectiveness is highest when administered within a few hours of the bite.

To prevent a bite:

• Wear protective clothing, use shoes and long pants when in areas where these spiders are found.
• Before wearing your clothes and shoes, make sure to check them to ensure no spiders are hiding.
• Maintain cleanliness and avoid leaving food or garbage exposed, as this can attract spiders.

These preventive measures are essential for minimizing the risk of encountering and getting bitten by Banana spiders.

Can Brazilian spiders kill humans?

Brazilian wandering spiders (Phoneutria nigriventer) are venomous and can potentially kill a human with a single bite. Their venom contains a potent neurotoxin that can cause severe pain, paralysis, and even death. 

Are Brazilian spiders poisonous?

Yes the venom of this spider is poisonous, that can cause death. While Brazilian wandering spiders are potentially dangerous, actual bites are relatively rare.

By adopting preventive measures and promptly seeking medical attention if bitten, the risk of serious complications can be significantly reduced.

Can you keep Brazilian spiders as pets?

It is strongly advised against keeping wandering spiders as pets due to their venomous nature and the potential risk to human safety.

Managing these spiders in captivity demands specialized knowledge and handling procedures to minimize the risk of bites.

Final Thoughts:

The Brazilian wandering spider, banana spider, or armed spider is a large and venomous arachnid found in Central and South America. While their potent venom can be harmful to humans, encounters are rare.

These nocturnal hunters have adopted various habitats, from rainforests to urban areas, and are associated with banana shipments. Understanding their appearance, behavior, and habitat is crucial for minimizing risks.

Seeking immediate medical attention after a bite is essential, as antivenom is available but most effective when administered promptly. Despite their fearsome reputation, the Brazilian spider remains a captivating and potentially dangerous species.

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The World’s Most Venomous Spider: The Brazilian Wandering Spider

Published: August 10, 2023

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Few things fear people’s hearts, like the mention of venomous spiders. According to the Guinness World Records , venomous spiders are some of the most dangerous creatures on Earth, and the Brazilian Wandering Spider is the world’s most venomous spider. This elusive arachnid is found in the rainforests of South America, more specifically in Brazil, Argentina, and French Guiana. ‘

It is considered one of Brazil’s most significant public health threats, with a potent venom capable of causing extreme pain, paralysis, and even death. Despite its fearsome reputation, however, the Brazilian Wandering Spider is a fascinating and unique creature with many incredible features that make it stand out from other spiders.

Jump ahead to any section below!

Brazilian Wandering Spider’s Habitat And Range

The Brazilian Wandering Spider is found in the rainforests of South America. These rainforests are the world’s largest and most biodiverse terrestrial ecosystems, covering an area of approximately 6.7 million square kilometers. This equates to roughly 40% of the total area of South America and spans nine countries, including Brazil, Peru, and Colombia.

The Amazon rainforest, the most extensive rainforest on Earth, plays an essential role in the Brazilian Wandering Spider’s habitat and range. The spider relies heavily on the dense canopy of trees in these rainforests for shelter and protection. The Amazon rainforest also provides the spider with an abundant prey source, including insects, small mammals, and other spiders.

The South American rainforests are characterized by their warm and humid climate, which creates the ideal conditions for the Brazilian Wandering Spider to thrive. These ecosystems also have a high rainfall throughout the year, which sustains the dense vegetation and creates an ideal environment for spiders to hunt and reproduce.

Check out: Uncovering The Enigma Of The Greenland Shark .

Specific Locations The Brazilian Wandering Spider Is found

The Brazilian Wandering Spider is most commonly found in Brazil. It can also be found in other parts of South America, such as Argentina and French Guiana. In Brazil, the spider can be found in various regions. This includes the Amazon rainforest, the Atlantic forest, and the Caatinga ecosystem.

The Atlantic forest, a tropical forest that spans the Brazilian coast, is also an important habitat for the Brazilian Wandering Spider. This ecosystem is under threat due to deforestation and urbanization. This has resulted in the loss of the spider’s natural habitat.

In French Guiana, the spider is present in the Guiana Amazonian Park, a protected area of the Amazon rainforest managed by the French government. The Guiana Amazonian Park is home to an array of biodiversity, including monkeys, jaguars, and over 400 species of birds. This makes it an important region for the Brazilian Wandering Spider’s survival.

Brazilian Wandering Spider’s Characteristics

It is a remarkable arachnid species found in the rainforests of South America. It has numerous unique characteristics from other spiders. The Spider is large and intimidating, measuring up to 10 inches (25 cm) in leg span. Its body size ranges from 0.98 to 1.77 inches (2.5 to 4.5 cm) in length. This makes it one of the biggest spider species in the world. It has eight long and hairy legs, which help it move quickly and climb trees effortlessly.

The spider is striking, with a shiny brown or black body covered in short fine hairs. Its legs are also covered in fine hairs with dark stripes or spots. These markings have a unique pattern that helps to identify the spider from other species. Unlike most spiders, the Brazilian Wandering Spider doesn’t have a distinct web-spinning organ. But instead moves around the forest floor and trees in search of its prey.

Behavioral Patterns

They are aptly named because they are known to wander about and can cover a great distance while searching for food and mates. It’s primarily active at night and is a solitary hunter that preys on insects, spiders, rodents, and even small snakes. It has a unique hunting technique where it grabs its prey with its front legs and sinks fangs into it, injecting a potent venom that can quickly immobilize and kill its victim. Interestingly, this spider can adjust the amount of venom it injects to fit the size and the species of its prey, a skill unique to this spider species.

During the mating season, the Brazilian Wandering Spider’s behavior changes drastically. The males will approach females cautiously, tapping on the female’s web to signal their interest. They then perform a complex courtship display that involves waving their front legs, drumming their pedipalps, and vibrating on webs. The more intricate the display, the higher the chances of mating with the female.

Brazilian Wandering Spider’s Venom

The venom of the Brazilian Wandering Spider is considered one of the deadliest in the world. The potency of the venom is due to the presence of a potent neurotoxin called PhTx3. This toxin is responsible for the spider’s ability to paralyze its prey and defend itself from predators.

In scientific studies, the venom of the Brazilian Wandering Spider has proven to be significantly more toxic than other venomous spiders, such as the Black Widow and the Brown Recluse. The effectiveness of this venom is a result of its unique chemical structure, which allows it to attack the nervous system of its victim and cause significant damage.

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Effects Of Venom On Humans And Animals

The effects of the venom of the Brazilian Wandering Spider can be devastating. When bitten, victims may experience severe pain, muscle spasms, and even paralysis. In extreme cases, the venom can cause respiratory failure, resulting in death.

While the venom initially causes pain and discomfort, it can lead to severe, long-lasting symptoms. In addition to causing physical harm, the venom can also have psychological effects, leading to anxiety, panic attacks, and even PTSD.

Animals are also susceptible to the venom of the Brazilian Wandering Spider . Small animals, such as mice and birds, are often preyed upon by the spider, while larger animals, such as dogs and cats, can be bitten accidentally.

Public Health Threat And Prevention

The Brazilian Wandering Spider is a significant public health threat in Brazil, with hundreds of bites reported yearly. The spider has a wide distribution throughout the country, and its venom is particularly toxic, making it a serious risk to human health.

Also, the spider is especially dangerous because it is highly aggressive and can be found in homes, gardens, and public spaces. This means that anyone can encounter the spider, regardless of location or occupation, making it difficult to prevent bites.

Measures Taken To Prevent Bites And Treat Victims

To prevent bites from the Brazilian Wandering Spider, it is essential to take steps to reduce the risk of encountering the spider. This may include keeping homes and gardens free of clutter and debris, sealing windows and doors, and avoiding areas where the spider is known to live.

In the case of a bite, it is important to seek medical attention immediately. While no anti-venom is available, medical professionals can offer supportive care to alleviate symptoms and prevent complications.

Frequently Asked Questions

The Brazilian Wandering Spider’s venom contains a potent neurotoxin called PhTx3, which can cause extreme pain, muscle spasms, and paralysis in humans. This venom is 20 times more deadly than a rattlesnake’s and can cause respiratory failure in victims.

It is primarily found in South and Central America, especially in the Amazon rainforest. They hide in dark, moist environments such as piles of leaves, tree trunks, and burrows.

To avoid contact with the Brazilian Wandering Spider, it is important to inspect your surroundings, especially before putting on shoes or reaching into piles of debris. It is advisable to wear gloves and long sleeves when working outdoors or in areas where these spiders may be present. If you suspect a Brazilian Wandering Spider has bitten you, seek medical attention immediately.

Overall, the Brazilian Wandering Spider is a fascinating and deadly spider that deserves respect and caution. Though its venom is incredibly potent, the spider itself is a remarkable creature. Its ability to move quickly and seamlessly across the ground makes it a formidable predator in its native habitats. 

Despite its fearsome reputation, we must learn to coexist with this remarkable arachnid, preserving its unique place in the natural world. Given the immense diversity and beauty of our planet’s biodiversity, the Brazilian Wandering Spider reminds us that we still have much to learn about the remarkable creatures that share our planet.

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Southeastern Wandering Spider (Anahita punctulata )

Detailing the physical features, habits, territorial reach and other identifying qualities of the southeastern wandering spider.

The tropical Southeastern Wandering Spider is an active hunter, making the most of a warm climate teeming with insect prey.

General characteristics.

Taxonomic Hierarchy

Identifying information.

Relative Size Comparison

Territorial Reach (A-to-Z)

Territorial Map*

Brazilian Wandering Spider (Phoneutria Nigriventer)

The Brazilian wandering spider (Phoneutria nigriventer), also known as the armed spider or banana spider, is a deadly spider native to South America. This large, venomous arachnid is widely recognised as one of the most venomous spiders in the world. With a range of fascinating behaviours and unique adaptations, the Brazilian wandering spider has become a subject of interest for scientists and enthusiasts alike.

Physical Characteristics

Brazilian wandering spiders are known for their robust build, long legs, and powerful fangs. They are large spiders, with an average leg span of up to 6 inches (15 cm) and a body length that ranges from 1.7 to 2 inches (4.3 to 5 cm). Their size makes them particularly intimidating to encounter, as they are one of the largest spiders in their region.

The spider’s colouration varies depending on the species, but most Brazilian wandering spiders are brownish in colour with black or dark markings. This colouration enables them to blend into their natural habitat, making it easier for them to ambush their prey.

Anatomically, these spiders have a robust body, long and thick legs, and powerful fangs that can deliver venomous bites. Their eyes are arranged in two rows, with a total of eight eyes, which gives them a wide field of vision and the ability to detect motion from various angles. Their chelicerae (fang-bearing mouthparts) are large and powerful, capable of piercing the skin and delivering venom to their prey.

Brazilian wandering spiders are primarily found in the tropical rainforests of South America, especially in Brazil, and one species in North America. Their preferred habitat includes a variety of environments ranging from the forest floor to trees and shrubs. The dense vegetation of the rainforest provides them with ample hiding spots, making it easier for them to ambush their prey.

These spiders are highly adaptable and can survive in a range of environments. They have even been found in human settlements, particularly in rural areas where there is less disturbance. In such cases, they may seek refuge in homes, barns, or other structures, especially during periods of heavy rain or when searching for food.

Diet and Hunting Techniques

Brazilian wandering spiders are carnivorous predators that primarily feed on insects, other spiders, and small vertebrates such as lizards and frogs. They have a diverse diet and can consume a wide range of prey, depending on their size and availability.

Unlike many other spiders, Brazilian wandering spiders do not spin webs to catch their prey. Instead, they actively hunt for food, relying on their acute senses, speed, and agility to catch their prey. They use a combination of stealth and ambush tactics to get close to their prey, and then swiftly strike with a venomous bite, immobilising their victim.

The wandering behaviour of these spiders is what gives them their name. Instead of building a permanent web and waiting for prey to come to them, Brazilian wandering spiders actively search for food. This makes them highly mobile and increases their chances of encountering a wide variety of prey.

When threatened, Brazilian wandering spiders are known for their aggressive behaviour. They may raise their front legs and display their fangs in a defensive posture. This behaviour is a warning to potential predators that they are armed with venom and ready to strike if necessary.

Reproduction

The reproduction process in Brazilian wandering spiders begins with courtship rituals. Males initiate mating by approaching females and signalling their intentions through vibrations and leg movements. Once the female is receptive, the male deposits his sperm into the female’s reproductive organs.

After mating, the female lays a clutch of eggs and guards them until they hatch. The spiderlings then disperse to start their independent lives. As they grow, they moult several times, shedding their exoskeletons and developing into mature spiders.

The Brazilian wandering spider venom is highly potent and contains a mix of toxins, including neurotoxins, proteins, and enzymes. This venom is highly effective at immobilising their prey, making it easier for the spider to consume it.

In humans, the venom can cause a range of symptoms, including intense pain, swelling, excessive sweating, blurred vision, and elevated heart rate. In rare cases, Brazilian wandering spider bite can lead to severe complications or even death. However, with prompt medical treatment, most victims recover without long-term effects.

Brazilian Wandering Spider and Humans

Brazilian wandering spiders are known to occasionally enter human settlements, especially in rural areas. While these encounters can be unnerving, the spiders generally prefer to avoid confrontation with humans.

If you encounter a Brazilian wandering spider, it is important to stay calm and avoid provoking it. If you are bitten, seek medical attention immediately, as prompt treatment is crucial for minimising the effects of the venom.

Conservation Efforts

Conservation efforts are essential for Brazilian wandering spiders, as their natural habitat is increasingly threatened by deforestation, agriculture, and urbanisation. Protecting the rainforests and other natural habitats of these spiders is crucial for their survival.

Interesting Facts

• The venom of the Brazilian wandering spider is being studied for potential medical applications, including pain relief and anti-venom development.
• Despite their reputation as highly venomous spiders, Brazilian wandering spiders play an important role in controlling insect populations in their ecosystems.
• These spiders are also known as “banana spiders” because they have been found in shipments of bananas.

The Brazilian wandering spider (Phoneutria nigriventer) is a remarkable arachnid with unique adaptations and behaviours. Despite their fearsome reputation, these spiders are an essential part of their ecosystems and play a vital role in controlling pest populations. Understanding and respecting these spiders is crucial for their conservation and coexistence with humans.

Sam loves to learn about animals and their habitats. He has been a nature lover from a very young age, and has been writing papers and articles about wildlife for as long as he can remember.

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AnimalBehaviorCorner

Brazilian Wandering Spider

Brazilian Wandering Spider , scientifically known as Phoneutria, emerges as a captivating enigma in the realm of arachnids.

Renowned for its formidable reputation as one of the world’s most venomous spiders , Phoneutria embodies a plethora of intriguing traits that have captured the curiosity of enthusiasts and researchers alike.

From its distinctive appearance and neurotoxic venom to its nomadic hunting strategies and unique mating behaviors , this remarkable spider species holds a wealth of fascinating secrets waiting to be unraveled.

Join us as we embark on a journey to explore the captivating world of the Brazilian Wandering Spider, shedding light on its captivating characteristics and dispelling myths that have shrouded its true nature.

1. Taxonomy and Distribution of the Brazilian Wandering Spider

A. scientific classification of phoneutria.

The Brazilian Wandering Spider, scientifically referred to as Phoneutria, occupies a distinct place within the arachnid taxonomy.

Belonging to the family Ctenidae, this spider genus is further categorized into several species, each boasting unique traits and behaviors .

Phoneutria’s taxonomic position not only distinguishes it from its arachnid counterparts but also underscores its intriguing evolutionary journey.

B. Native Habitat in South and Central America

Endemic to the lush landscapes of South and Central America, the Brazilian Wandering Spider finds its natural haven within these diverse regions.

From the rainforests of the Amazon to the tropical stretches of the Caribbean, Phoneutria has adapted to a range of environments over the course of its evolution.

The spider’s ancestral ties to these regions are tightly woven into their behaviors , anatomy, and survival strategies.

C. Preference for Tropical Rainforests and Urban Areas

Within its native territories, the Brazilian Wandering Spider exhibits remarkable versatility in its chosen habitats.

While it thrives amidst the vibrant biodiversity of tropical rainforests, it has also displayed a propensity for urban locales.

Phoneutria’s adaptability has led it to establish a presence in urban areas, where it often finds shelter in crevices, gardens, and even human dwellings.

This adaptability to both wild and urban spaces further showcases the spider’s resilience and capacity to thrive in varying conditions.

2. Physical Characteristics of the Brazilian Wandering Spider

A. size, coloration, and distinctive markings.

The Brazilian Wandering Spider , a creature of remarkable visual intrigue, boasts an array of captivating physical attributes.

Ranging in size from a few centimeters to several inches, Phoneutria showcases a size diversity that reflects the breadth of its genus.

Its coloration varies across species, encompassing shades of brown, black, and gray, often accompanied by intricate patterns and markings that adorn its exoskeleton.

These unique markings serve not only as a visual spectacle but also as essential components of its survival toolkit.

B. Camouflage and Defense Mechanisms

The Brazilian Wandering Spider’s appearance is a masterpiece of evolution, meticulously crafted to ensure both survival and predation .

Its coloration and markings are tailor-made for blending seamlessly into its surroundings, granting it a potent advantage in ambushing prey and evading predators . Moreover, these markings also play a role in its defense mechanisms.

When threatened, Phoneutria adopts a defensive posture, raising its front legs and revealing its striking markings, a visual warning to potential threats. This dual-purpose camouflage and defense strategy exemplify nature’s ingenuity at its finest.

C. Sexual Dimorphism: Unveiling Gender Differences

A fascinating facet of the Brazilian Wandering Spider lies in the realm of sexual dimorphism , where gender-based variations manifest in pronounced ways.

Females tend to be larger and more robust than their male counterparts, showcasing a size disparity that has evolved in tandem with their roles in reproduction and hunting .

Beyond size, other characteristics, such as leg structure and coloration, also exhibit subtle differences between male and female Phoneutria specimens.

This divergence in physical traits adds depth to our understanding of the species’ intricate biology and behavior .

In exploring the physical characteristics of the Brazilian Wandering Spider , we uncover a canvas painted with size diversity, intricate coloration, and unique markings.

These features, finely tuned by evolution, contribute to its prowess in camouflage and defense, while the fascinating interplay of sexual dimorphism further enriches our perception of this captivating arachnid species .

3. Venomous Nature of the Brazilian Wandering Spider

A. potent neurotoxic venom: a silent lethal weapon.

The Brazilian Wandering Spider, known scientifically as Phoneutria, harbors a venomous arsenal that stands as a testament to nature’s intricate design.

This spider’s venom contains a potent concoction of neurotoxic compounds, tailored by evolution to incapacitate its prey swiftly and efficiently.

The neurotoxins interfere with nerve cell communication, leading to paralysis and ensuring that Phoneutria’s quarry is rendered immobile and defenseless, setting the stage for a successful meal.

B. Effects on Prey and Human Hazard

When a victim succumbs to the Brazilian Wandering Spider’s venom , the effects are a symphony of paralysis and predation .

The venom’s impact on the prey’s nervous system results in swift immobilization, offering the spider a decisive advantage in subduing its catch.

While this venomous efficiency is well-adapted for predation, it also underscores the potential danger to humans.

A bite from Phoneutria can lead to a series of neurotoxic reactions, with varying degrees of severity depending on factors such as the individual’s age and overall health.

While human envenomations are relatively rare, they can result in a range of symptoms, from localized pain and swelling to more severe neurological effects.

C. Recorded Cases of Envenomations: Unraveling the Symptoms

Throughout history, documented cases of Phoneutria envenomations have offered insights into the spider’s potential threat to humans .

Symptoms typically include intense pain at the bite site, accompanied by swelling and redness . In some instances, victims have reported systemic reactions, such as muscle cramps, elevated heart rate, and even breathing difficulties.

Swift medical attention and the administration of antivenom have proven effective in mitigating the severity of these symptoms.

These cases serve as a reminder of the delicate balance between the Brazilian Wandering Spider’s potent venom and the potential risks it poses to those who unwittingly encounter it.

4. Hunting and Diet of the Brazilian Wandering Spider

A. hunting techniques and wandering behavior.

The Brazilian Wandering Spider, scientifically known as Phoneutria, unveils a mesmerizing repertoire of hunting techniques that set it apart as a master predator .

Displaying an agile and nomadic behavior , Phoneutria does not confine itself to the confines of a web. Instead, it actively prowls its surroundings, tirelessly searching for potential prey.

This dynamic wandering behavior ensures that its chances of encountering a variety of food sources are maximized, showcasing a strategic approach to sustenance.

B. Active Hunting Triumphs Over Web-Building

Unlike its web-weaving counterparts, the Brazilian Wandering Spider relies on a more hands-on approach to securing its next meal.

While weaving webs might seem an efficient method, Phoneutria’s active hunting strategy offers a distinct advantage in versatility.

By forgoing the constraints of a stationary web, it can tailor its approach to suit different environments and prey types, adapting its tactics on the fly.

This adaptability demonstrates the spider’s remarkable ability to adjust its methods for optimal results.

C. Diverse Prey Spectrum: Insects to Small Vertebrates

Phoneutria’s diet is a testament to its prowess as an opportunistic predator . Its menu spans a diverse range of creatures, from insects like crickets and cockroaches to small vertebrates such as lizards and frogs , and even small rodents.

This wide-ranging palate highlights its ecological significance in controlling various populations within its habitat.

By consuming creatures both large and small, Phoneutria ensures a balanced ecosystem, playing a crucial role in maintaining biodiversity and ecological equilibrium.

5. Mating and Reproduction of the Brazilian Wandering Spider

A. courtship rituals and behaviors: a complex affair.

The Brazilian Wandering Spider, scientifically referred to as Phoneutria, reveals a captivating array of courtship rituals and behaviors that form the cornerstone of its reproductive cycle.

Courtship among these arachnids is a complex affair, involving intricate dances and displays that serve as both communication and assessment.

Male Phoneutria employs a combination of visual cues, vibrations, and tactile interactions to court potential mates.

This elaborate courtship process highlights the significance of precise communication in the delicate dance of reproduction .

B. Cannibalistic Tendencies: A Post-Mating Phenomenon

An aspect that sets Phoneutria’s mating process apart is the notorious cannibalistic tendency exhibited by females after mating.

Following successful mating, females may exhibit an inclination to consume their partners. This seemingly counterintuitive behavior has evolutionary underpinnings.

It is believed that this cannibalistic act not only provides the female with a much-needed nutritional boost but also eliminates potential competitors and safeguards the male’s investment in the next generation.

This intriguing behavior sheds light on the complexities of reproductive strategies within the species.

C. The Unique Mating Plug Phenomenon: A Puzzling Enigma

A distinctive feature in Phoneutria’s reproductive saga is the enigmatic mating plug phenomenon. After mating, male Phoneutria deposit a specialized substance that forms a plug within the female’s reproductive tract.

This plug is believed to serve multiple purposes. It may prevent other males from mating with the female, thus ensuring the successful transmission of the mating male’s genetic material.

Additionally, it might aid in sealing off the female’s reproductive tract, potentially protecting her from external pathogens.

This phenomenon underscores the intricate interplay of biological strategies that contribute to the species’ reproductive success.

6. Human Interaction and Urban Legends of the Brazilian Wandering Spider

A. occasional presence in urban areas: nature in our midst.

The Brazilian Wandering Spider, scientifically known as Phoneutria, has carved a niche for itself not only in the wild but also in the fabric of urban environments.

While its primary habitats are the lush landscapes of South and Central America, Phoneutria occasionally ventures into human -inhabited spaces. Its adaptability allows it to find shelter in gardens, crevices, and even within homes.

This coexistence with humans adds an intriguing dimension to our encounters with this enigmatic arachnid .

B. Debunking Misconceptions: Separating Fact from Fiction

The presence of the Brazilian Wandering Spider has sparked a plethora of misconceptions and exaggerated tales, contributing to the creation of urban legends.

Stories of spiders leaping from banana bunches or hiding under toilet seats have become part of modern folklore, often fueled by sensationalism.

It’s crucial to sift through these tales and recognize that while Phoneutria’s venom is potent, the likelihood of encountering a dangerous encounter is relatively low.

Separating fact from fiction empowers individuals to approach these creatures with accurate knowledge.

C. Importance of Proper Education: Identifying Friend from Foe

Education plays a pivotal role in fostering a harmonious coexistence between humans and the Brazilian Wandering Spider .

Learning to identify and understand the behaviors of Phoneutria species enhances safety for both humans and the spiders themselves.

Instead of succumbing to unwarranted fear, individuals can take steps to reduce the chances of accidental encounters and, if necessary, engage in responsible removal methods.

By arming themselves with knowledge, individuals can navigate encounters with urban-dwelling Phoneutria specimens with confidence and respect.

7. Brazilian Wandering Spider Conservation and Misunderstanding

A. significance of phoneutria in ecosystem dynamics.

The Brazilian Wandering Spider , scientifically termed Phoneutria, assumes a pivotal role within its ecosystem, contributing to a delicate balance of populations and interactions.

As a top-tier predator , it plays a crucial part in controlling insect and small vertebrate populations, preventing unchecked growth that could disrupt the ecosystem’s equilibrium.

By maintaining these population dynamics, Phoneutria ensures the health and stability of its habitat, highlighting its significance beyond its ominous reputation.

B. Impact of Fear and Misunderstanding: Hindrances to Conservation

Despite its ecological contributions, the Brazilian Wandering Spider often falls victim to fear-driven misconceptions that negatively impact conservation efforts.

Misunderstandings surrounding its behavior and potential danger can lead to unwarranted extermination campaigns and habitat destruction.

Fear-driven reactions not only disrupt the natural balance but also hinder opportunities to study and appreciate the species for its ecological significance.

Addressing these misconceptions is crucial to ensuring the spider’s survival and maintaining the health of its ecosystems.

C. Efforts to Dispel Myths and Promote Coexistence

Efforts to conserve the Brazilian Wandering Spider are interwoven with endeavors to educate and dispel myths.

By providing accurate information and dispelling exaggerated tales, conservationists aim to reshape public perception.

Collaborative initiatives emphasize coexistence, highlighting the importance of responsible behavior when encountering Phoneutria.

Educating communities about the spider’s role, behavior, and conservation status fosters an environment where fear gives way to appreciation, and where balanced cohabitation becomes a reality.

8. Research and Medical Significance of the Brazilian Wandering Spider

A. ongoing scientific research on phoneutria venom.

The Brazilian Wandering Spider , Phoneutria, has garnered significant attention from the scientific community due to the unique properties of its venom.

Ongoing research delves into the intricate composition of the venom, aiming to unlock its mysteries and potential applications in various fields.

The diverse array of compounds within the venom, particularly its neurotoxic components, has attracted interest for their potential medical and therapeutic implications.

B. Antivenom Development and Therapeutic Prospects

One of the most promising areas of research surrounding Phoneutria lies in the development of antivenoms and therapeutic agents.

The venom’s potent neurotoxic effects on the nervous system have spurred efforts to create targeted treatments for conditions such as chronic pain and neurological disorders .

Additionally, the potential for antivenoms holds promise in mitigating the effects of envenomations, offering a lifeline for individuals who encounter these spiders .

This focus on harnessing the venom’s properties for positive medical outcomes highlights the transformative potential within this enigmatic arachnid .

C. Balanced Perspectives: Navigating Ethical and Scientific Endeavors

While research on the Brazilian Wandering Spider’s venom offers tremendous potential, it necessitates a balanced perspective.

As researchers probe the venom’s properties, ethical considerations arise, including the well-being of the spiders and their ecosystems.

A holistic approach acknowledges the value of understanding Phoneutria’s natural behaviors and conserving its habitats.

This balanced perspective extends to utilizing the venom’s potential responsibly, ensuring that breakthroughs are achieved while respecting the complex interplay of science and nature.

9. Frequently Asked Questions about the Brazilian Wandering Spider

What is the brazilian wandering spider.

The Brazilian Wandering Spider , scientifically known as Phoneutria, is a venomous arachnid found in South and Central America. It’s notorious for its potent venom and is considered one of the most venomous spiders in the world.

Is the Brazilian Wandering Spider dangerous to humans?

Yes, the Brazilian Wandering Spider’s venom contains potent neurotoxins that can cause a range of symptoms in humans , from localized pain and swelling to more severe reactions. While bites are relatively rare, it’s advisable to exercise caution when encountering these spiders.

What is the spider’s habitat?

The Brazilian Wandering Spider is native to tropical rainforests of South and Central America. However, it’s adaptable and can also be found in urban areas, such as gardens and houses.

How does the Brazilian Wandering Spider hunt?

Unlike many spiders that build webs, Phoneutria is an active hunter. It roams its environment in search of prey, relying on its keen senses to detect vibrations and movements.

Are Brazilian Wandering Spiders aggressive toward humans?

Brazilian Wandering Spiders are not naturally aggressive towards humans and will typically only bite in self-defense. However, caution is advised, especially in areas where these spiders are known to inhabit.

Can the Brazilian Wandering Spider’s venom be used for medical purposes?

Yes, research is ongoing into the potential medical applications of Phoneutria’s venom. Its neurotoxic properties have sparked interest in pain management and neurological treatments.

Is the spider’s reputation for crawling into banana shipments true?

While there have been stories of Brazilian Wandering Spiders being found in shipments of bananas, these occurrences are extremely rare. Spiders are unlikely to survive the conditions of shipping and storage.

How can I stay safe around Brazilian Wandering Spiders?

To stay safe, it’s important to be cautious when encountering spiders in their natural habitat. Avoid provoking or handling them, especially if you’re unsure of their identity. If you suspect you’ve been bitten, seek medical attention promptly.

Are there any efforts to conserve the Brazilian Wandering Spider?

Conservation efforts for the Brazilian Wandering Spider are intertwined with public education and dispelling myths. Recognizing its role in ecosystems and promoting coexistence are essential steps in preserving this unique species.

What can I do if I find a Brazilian Wandering Spider in my home?

If you encounter a Brazilian Wandering Spider in your home, it’s advisable to contact local pest control professionals who can safely remove the spider without causing harm.

In the intricate tapestry of nature, the Brazilian Wandering Spider , Phoneutria, emerges as a creature of both fascination and caution.

Its venomous nature and captivating behaviors have earned it a place among the most enigmatic arachnids .

As we continue to explore its world, debunk myths, and understand its vital role in ecosystems, we find a delicate balance between awe and respect.

Armed with knowledge, we navigate the realm of Phoneutria, appreciating its complexity while fostering coexistence, a testament to the intricate dance between humans and the natural world.

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Ctenidae (Wandering Spiders)

The spider family Ctenidae, commonly known as Wandering Spiders, have been sighted 53 times by contributing members. Based on collected data, the geographic range for Ctenidae includes 11 countries and 7 states in the United States. Ctenidae is most often sighted indoors , and during the month of April .

• Pictures (10)

Taxonomic Hierarchy

• Kingdom: Animalia
• Phylum: Arthropoda
• Class: Arachnida
• Order: Araneae
• Suborder: Araneomorphae
• Family: Ctenidae

Common Name (AAS )

Wandering Spiders

Eugen von Keyserling, 1877

Sightings Overview

There have been 53 confirmed sightings of Ctenidae (Wandering Spiders), with the most recent sighting submitted on December 28, 2019 by Spider ID member hugo . The detailed statistics below may not utilize the complete dataset of 53 sightings because of certain Ctenidae sightings reporting incomplete data.

• Web: 8% of the time, Ctenidae spiders are sighted in a spider web (Sample size: 52)
• Sex:  2 female and 12 male.
• Environment:  Ctenidae has been sighted 28 times outdoors, and 30 times indoors.
• Outdoors: Man-made structure (13). Low foliage (3). Ground layer (7). Freshwater river, lake, stream (1). Forest (4).

Location and Range

Ctenidae (Wandering Spiders) has been sighted in the following countries: Brazil, Colombia, Costa Rica, Ecuador, France, Honduras, India, Mexico, Panama, Peru, United States.

Ctenidae has also been sighted in the following states: Alabama, Florida, Georgia, Kentucky, South Carolina, Tennessee, Texas.

Seasonality

Ctenidae has been primarily sighted during the month of April.

• February: 2
• September: 1
• November: 2
• December: 3

Genus: Acanthoctenus

Genus: Anahita

Genus: Ancylometes

Genus: Ctenus (Tropical Wolf Spiders)

Genus: Phoneutria

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• Spiders in US
• Parts of a Spider
• Life Cycle of a Spider
• Where do Spiders Live
• What do Spiders Eat
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• Where do Spiders go in Winter
• Spider Ballooning
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• Spider Predators

Southeastern Wandering (Anahita punctulata)

Have you ever heard of Southeastern wandering spiders ? They’re part of the big Ctenidae family and come from the Anahita group. These spiders can be found in various places in America.

Scientific Classification

• Family: Ctenidae
• Genus: Anahita

Physical Description and Identification

• Size: They are between 0.20 inches and 1.56 inches in length, with females larger than males.
• Color: These spiders have a brown or tan body.
• Other Characteristic Features: They have long legs like most other wandering spider species.

The eggs are small and round enclosed safely inside a silken sac.

Spiderlings

Though sufficient details remain unavailable, they stay with their kin until maturation and then disperse to be on their own.

Like other wandering spiders, this species too does not spin webs but attacks their prey by suddenly attacking them from their hidden den.

Are Southeastern Wandering Spiders Venomous?

Yes, Southeastern wandering spiders do have venom. It helps them catch and eat their food. But for most people, it’s not super dangerous.

Can Southeastern Wandering Spiders Bite?

Sure can! Like many spiders, they might bite if they get scared. It can be a bit painful, but usually, it’s okay. Best to be gentle with them!

Photo Credit: Kathy Hardy

Ecological Importance and Behavior of Southeastern Wandering Spider

Southeastern wandering spiders play an essential role in maintaining the balance of their ecosystems. By preying on small insects, they help control the population of potential pests, contributing to a healthier environment. Their nomadic nature and ambush-hunting tactics showcase their adaptability and resilience, making them fascinating subjects for arachnological studies.

Natural Predators and Prey-Predator Dynamics: In the wild, these spiders face threats from birds, larger spiders, and other predators. The sophisticated dance between predator and prey is a vital aspect of their existence, influencing their behavior, life cycle, and the broader ecological balance.

Relationship with Humans: While encounters with humans are infrequent, it’s crucial to foster a respectful and informed relationship with these spiders. Understanding their role in the ecosystem and acknowledging their generally non-threatening nature helps in demystifying these creatures, paving the way for coexistence and appreciation.

Quick Facts

Did you know.

• Like most other species of their family, the Southeastern spider also bears a close resemblance to the wolf spiders .

In summary, the Southeastern wandering spiders are a remarkable testament to the adaptability and resilience of arachnids.

Other Spiders in this Family

Wandering spiders.

Phoneutria depilata

Phoneutria boliviensis

Phoneutria fera

Phoneutria nigriventer

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Watch CBS News

Giant Joro spiders can fly for miles and devour butterflies, but they're also very shy. Here's what to know as they spread.

By Li Cohen

June 6, 2024 / 7:01 PM EDT / CBS News

You may have heard about some not-so-itsy-bitsy venomous flying spiders that can soar with the winds, love to eat butterflies and are already appearing along the East Coast. They're called Joro spiders – and their lifestyle is just as interesting as their looks. 

Perhaps the most intriguing part? Despite their ability to parachute through the air and their large size, researchers have found that they are actually super shy  — in fact, they may be among the "'shyest' spiders ever documented," according to a report published by the University of Georgia last year. 

"We wanted to get to know the personality of these spiders and see if they're capable of being that aggressive," co-author  Andy Davis said of the report's findings. "It turns out they're not." 

Here's what to know about these arachnids as experts say they're making their way up from Georgia to New York and beyond. 

What do Joro spiders eat?

Researchers from Clemson University previously found that Joros like to dine on flying insects, but they aren't really picky about which ones. 

"These spiders don't seem to care what gets in their web; they're just as likely to eat brown marmorated stink bugs as they are to eat a Monarch butterfly," researcher David Coyle said in a press release from the university, adding that "they're a spider – and if something gets caught in their web, it's going to get eaten." 

At the end of the day, researchers say they're not likely to bite humans or pets, or, if you live in New York City, the giant rats that roam the trash bins. If and when the arachnids do end up in the Big Apple, they're more likely to munch on roaches or wasps. 

Where do Joro spiders come from? 

The yellow-and-gray-bodied Joros are an invasive species, meaning they are not native to the United States. According to the University of Georgia's Center for Invasive Species and Ecosystem Health, the spiders are native to East Asia and were first spotted in Georgia in 2014. It didn't take long, however, for them to end up "everywhere," Coyle said.

Coyle first spotted them in his backyard a few years ago, realizing he could see one of the critters about every two yards. Since they first hit Georgia, they've expanded their territory considerably. 

Where are Joro spiders in the U.S.?

Joros have been observed across several states since they first landed in Georgia. According to records submitted to iNaturalist , the spiders have been seen in Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, South Carolina, Tennessee, Virginia, West Virginia and Ohio. 

"Data show that this spider is going to be able to inhabit  most of the eastern U.S. ," Coyle said in October. "It shows that their comfort area in their native range matches up very well with much of North America. ... We expect the range of these things to continue expanding, likely to the north, and we've already seen that with some populations in Maryland." 

Are Joro spiders poisonous to humans? 

Technically, yes — but also no. Joro spiders are venomous, but they are not known to be aggressive and are much more scared of people than people are of them, which is really saying a lot. 

"They are harmless to people and reluctant to bite," Penn State Extension says. "And, if bites do occur, the venom is weak and not medically important ." 

If a bite does happen, the organization added, it's less painful than a bee sting, and any localized pain and redness would quickly resolve. 

In a report published last year, researchers from the University of Georgia analyzed 450 spiders from 10 different species to study their responses to minor disturbances. They found that while most spiders will freeze for less than a minute before resuming activity, Joro spiders essentially "shut down"  and won't move for more than an hour. The only other spider to exhibit a similar behavior is the Joro's cousin, the golden silk spider. 

"These spiders are really more afraid of you than the reverse," researcher Andy Davis said. 

Even if they do get so afraid that they try to bite you, Davis' team found that their fangs probably aren't even large enough to bite through the skin. 

Coyle said he's held the spiders "on countless occasions," as have his kids, and "there's really no danger" posed to people or pets. 

Should I kill Joro spiders?

Even though the spiders may make you squeamish and can appear quite scary, the arachnids are incredibly timid. Killing them, Coyle said, may not be necessary . 

"Pesticides work, but also, they are probably overkill because it will kill everything else, and there is a cost involved," he said, suggesting that the spiders be physically moved if they've crawled inside your house. "They seem to love structures. So, I just tell people to take a stick or broom and remove them." 

Davis has found in his research that while the spiders are an invasive species, they don't yet seem to have greatly impacted local ecosystems. However, more research on this front is needed. 

"People should try to learn to live with them ," he said. "If they're literally in your way, I can see taking a web down and moving them to the side, but they're just going to be back next year."

Even the pest control service  Orkin  says that "moving them away from homes or removing their webs may be sufficient."

How big are Joro spiders? 

According to Penn State Extension , adult female Joro spiders have bodies up to an inch long and a leg span of up to four inches. For reference, the average length of a human female's hand is 6.8 inches – meaning these spiders' leg spans would take up most of an average woman's hand. 

Adult male Joro spiders are "much smaller," PennState Extension said, with a body length just over a quarter of an inch. They also appear much more brown than females. 

Even bigger than the spiders, however, are their webs. Coyle found some webs spanning more than six feet. There are reports that the webs can be up to 10 feet wide . 

Can Joro spiders fly? 

They might not have wings, but they do like to take to the skies, in a manner of speaking. It's not "flying," per se, but the arachnids use a technique called "ballooning" in which they release their silk into the wind and let the currents take them on an adventure. 

According to Penn State Extension, spiderlings can move "tens to hundreds of miles" with this process, "so a storm blowing in the right direction at the right time of year may move them in large jumps."

Li Cohen is a senior social media producer at CBS News. She previously wrote for amNewYork and The Seminole Tribune. She mainly covers climate, environmental and weather news.

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Beware! The 18 Most Impressive Spiders From Around The World

Posted: June 14, 2024 | Last updated: June 14, 2024

Small, quick, and venomous spiders are one of the more dangerous and deadly species on the planet. From Black Widows killing and devouring male spiders to fuzzy wolf spiders who only attack when threatened, read on for some of the world's nastiest, most venomous, and lethal arachnids. Keep reading to learn more about these creepy critters.

Brown Recluse's Venom Is Medically Significant

When they bite their victim, the Brown Recluse releases a necrotic venom that prematurely kills cells and organs in the body. Thankfully, their venom does come with an upside.

The Brown Recluse is one of three spiders whose venom is medically significant in North America. Even so, their bite is no walk in the park.

Brazilian Wandering Spiders Are The Deadliest In The World

The Brazilian Wandering Spider is known as the deadliest spider in the world. Their venom causes its victim to experience hypothermia, high and low blood pressure, nausea, severe burning at the bite site, sweating, vertigo, and even blurred vision.

They are mainly found in South America, with one sub-species living in Central America.

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Brown Widows Cause Damage To The Nervous System

The Brown Widow or hour button spider is identified by its orange-yellow colored hourglass shape and the black and white patterns on the sides of its body. A relative to the infamous Black Widow, the Brown Widow produces neurotoxic venom that damages their victims' nervous system.

Thankfully, it is not deadly to humans.

Yellow Sac Spiders Are Painful But Not Lethal

Yellow Sac Spiders are identified by their pale yellow or beige coloring. Their bite isn't lethal to humans, but that doesn't mean it isn't one of the more painful bites out there.

This particular spider expels a necrotic toxin which is extremely painful and results in a whole lot of swelling.

Black Widow's Kill And Eat Their Mates

Known for the vibrant red hourglass shape on their back, Black Widow spiders are some of the deadliest of all. Ironically, humans aren't the only ones who have to watch out for widows.

After mating, this particular spider enjoys killing and eating the male. Black Widows are found all over the world.

Redback Spiders Release An Alpha-Latrotoxin

Native to Australia, Redback Spiders produce various toxins with their bites, but it's the alpha-latrotoxin that is not too fun for humans. A majority of the spider bites reported in Australia are that of the Redback Spiders.

Thankfully, while the bites are harsh with pain, chest pain, breathing difficulties, among other things, they are not lethal to humans.

Wolf Spiders Chase Their Prey Over Long Distances

Wolf Spiders are interesting, as they do not spin webs and have the energy and persistence to chase and hunt their prey over long distances. They will then pounce and bite, expelling a painful bite that is, thankfully, not lethal to humans.

Their bites usually result in inflamed skin and mild pain.

Funnel-Web Tarantulas Are Lethal

When it comes to spiders, Funnel-Web Tarantulas are very large, having a long body that can reach two inches. Dark in color, these spiders enjoy making their homes in burrows or in tree hollows.

Unfortunately, their strong and powerful fangs hold a toxin that is thought to be lethal to humans.

The Six-Eyed Sand Spiders Have A Painful Bite

The Six-Eyed Sand Spider can be found in the sandy regions of southern Africa. With their flattened bodies, they're also known as the six-eyed crab spiders. But don't let their interesting body formation fool you.

This species of spider has a very painful and toxic bite, resulting in life-threatening wounds if they become infected.

The Chilean Recluse Spiders Are Extremely Toxic

The Chilean Recluse Spider is thought to be the most dangerous of the recluse spiders. Native to South America, the Chilean Recluse's venom is extremely toxic to humans, sometimes resulting in the victim's death.

While no one wants the venom of this spider running through their veins, it is actually medically significant.

Camel Spiders Liquefy Its Victims Skin

Camel Spiders can grow to be between five and six inches, including their legs. Interestingly, there are many urban legends surrounding this spider, making its size up for debate!

Living in the hot deserts around the world, this spider uses digestive fluids to liquefy its victim's flesh. Somehow, their bite isn't deadly to humans.

The Sydney Funnel-Web Spiders Bite Has Caused 13 Deaths

Native to Australia, the Sydney Funnel Web Spider is one of the more feared spiders in the region. Between 1927-1980, there were 13 confirmed deaths as a result of a Sydney Funnel Web Spider bite.

The bite is known to be very painful, resulting in muscular twitching, breathing difficulty, and even disorientation and confusion.

Chinese Bird Spiders Venom Is Lethal For Rodents

The Chinese Bird Spider is a member of the tarantula family and is considered highly venomous. Known to live underground, these spiders tend to go after mice and other rodents.

In fact, it isn't really known the effect a Chinese Bird Spider's venom has on humans. But a small dose is lethal to mice.

Huntsman Spider Bites Result In An Irregular Pulse Rate

The Huntsman Spider is often referred to as a wood spider due to its preference to live in woodsy habitats. This particular arachnid is no small spider, with its legs growing a solid 11 inches.

They're known to inflict defensive bites on humans, resulting in irregular pulse rate, heart palpitations, a lot of pain, and swelling, among other things.

Mouse Spider Bites Cause Muscle Spasms

Mouse Spiders get their name from their unusual habitat and living situation, a burrow underground like that of a mouse. Their bite is similar to other spiders of the region, particularly the funnel-web spider with muscular twitching, breathing difficulty, and even disorientation and confusion.

Thankfully, there have been no recorded deaths as a result of a Mouse Spider bite.

White-Tailed Spiders Hunt Other Spiders With Their Painful Bite

White-Tailed Spiders can be found up and down southern Australia. And while other spiders tend to go after insects or rodents, these feisty arachnids do something else -- they hunt other spiders.

When it comes to humans, their venomous bite can cause pain, itchiness, swelling, headaches, and, in extreme cases, vomiting.

Goliath Birdeater Tarantula Is The Largest Spider In The World

Despite its name, the Goliath Birdeater Tarantula doesn't actually eat birds. In fact, its diet consists of worms. The largest spider in the world, the Goliath Birdeater Tarantula's body length can grow up to five inches and weigh six ounces.

With large fangs, this spider is venomous. Thankfully, their venom, while annoying, isn't lethal.

Fringed Ornamental Tarantula Bites Are Very Painful

The Fringed Ornamental Tarantula is native to Sri Lanka and is no walk in the park. While their bites aren't lethal, according to records, they are very painful and can cause muscle cramping and spasms.

This is a non-fatal spider that really shouldn't be on anyone's list to see in person.

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June 11, 2024

Giant Joro Spiders Are Coming: Here’s What to Expect

Millions of hand-size Joro spiders are moving up the East Coast. Don’t panic

By Stephanie Pappas

Joro spiders such as this one are native to East Asia and likely hitched a ride to the U.S. on shipping containers.

Allen Creative/Steve Allen/Alamy Stock Photo

Worrisome headlines about venomous Joro spiders marching up the East Coast have been spreading across the Internet like, well, venomous Joro spiders marching up the East Coast.

The spiders are indeed on the move. The good news is that the headlines are circulating much faster than the creatures themselves. The better news is that these arachnids, also known as Trichonephila clavata, don’t readily bite, don’t kill humans and—contrary to some social media myths—can’t fly.

“They are not going to hurt you; they are not going to hurt your kids; they are not going to hurt your pets,” says Erin Grabarczyk, a biologist at Valdosta State University, who has studied the spiders’ dietary habits .

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Joro spiders are native to East Asia. They were introduced to the U.S. in 2013, when they were first spotted in Georgia, and probably arrived by hitching a ride on a shipping container, says Andy Davis, a University of Georgia scientist, who studies Joro spiders’ behavior and physiology. With their four-inch leg span, flashy black-and-yellow coloration and huge, golden-hued webs, these spiders aren’t subtle. But they’re also shy and docile. A 2023 study by Davis and one of his students, published in the journal Arthropoda , tested how several spider species reacted to a stressor (a light puff of air) and found that while most of them did so by freezing for under a minute, Joro spiders froze for more than an hour.

Ella Blakely, a fourth-year undergraduate student at Davis’s lab, can personally attest to the Joro’s retiring nature. For a study on whether Joro spiders eat native monarch butterflies that she co-authored with Davis, Blakely had to reach right into the arachnids’ webs to retrieve entangled butterflies. The spiders “would just kind of sit there,” she says. “They wouldn’t react, and they wouldn’t come out and bite us.”

Joro venom is made for subduing small insect prey, says Kelly Oten, a forest health researcher at North Carolina State University, who studies invasive species . The Joro spider’s bite, if you can manage to get one, is less painful than a bee sting and does not require medical intervention, Oten says.

It is true, however, that the Joro is on a probably unstoppable march to conquer the East Coast. There are now millions of these spiders in the Southeast, Davis says, and they are spreading. There have been some far-flung sightings, including in Oklahoma, Maryland and West Virginia, according to the community-science website Joro Watch , where individuals can report their own observations. Most of these have likely been one-off occurrences in which a spider had accidentally hitched a ride on a car, however. Without human assistance, Oten says, the spiders would naturally disperse at a rate of about 10 miles per year.

They mostly spread by “ballooning,” which involves using a thread of silk to catch the wind and float like a dandelion seed. This mode of transport has raised fears of airborne spider armies, but there’s no need to worry, Grabarczyk says. Joro spiders only balloon as young, tiny spiderlings . Adults are slow and awkward walkers when they are not on their webs.

Davis’s lab and others have found that the spiders are hardy and capable of surviving cold winters . Their native range takes them from chilly northern Japan to balmy Taiwan. “They’re very adept at living in a wide variety of climates, and those climates definitely overlap with what we see in the U.S. from Maine down to Florida,” Davis says. His research also finds that the spiders thrive in busy urban areas , including near roads and around buildings.

In other words, the spiders will likely make their way out of the Southeast into more northern states, and they’ll likely build webs in places where people will see them. This will probably happen more slowly than some of the headlines suggest, Oten says. “It’s not something the majority of the East Coast is going to have to worry about this year,” she says. “But in the next decade or so? Maybe.”

What is still a mystery is what impact the Joro spiders will have on the native ecosystem. Grabarczyk and her colleagues have found that Joro spiders generally chow down on whatever insects happen to fly by , she says. The arachnids would rather not eat monarch butterflies, whose bad-tasting toxins make them a last resort for spider snacks, which is a hint that one of North America’s most iconic insects will survive the Joro onslaught, says Emma Hobbs, who recently received a bachelor of science degree from the University of Georgia and co-authored the monarch study with Davis and Blakely. But researchers agree that more study is needed to find out whether Joro spiders will outcompete native spiders or otherwise damage East Coast ecology.

So far, the Joro spider doesn’t overlap in range with the spotted lanternfly ( Lycorma delicatula ), an invasive insect that coincidentally arrived in Pennsylvania from Asia around the same time the spider landed in the U.S. Southeast. It’s likely their ranges could overlap soon, though, Oten says, because both are now found in separate parts of North Carolina. When the two species do meet, it could be an interesting matchup Grabarczyk says. “I don’t think there’s any reason to think that [Joros] would not eat the spotted lanternfly.”

Because spotted lanternflies are an agricultural pest, people have been encouraged to kill them on sight. That’s not the situation with the Joro spider, which is better left alone, Davis says. “If it does take up residence in your backyard, it will be there for three or four months in the same place,” he says. “You can almost get to know that spider. Give it a name. Show your kids that spider. Show them what spiders do.… This almost gives you an unprecedented educational opportunity.”

Are 'giant, flying' joro spiders really taking over the U.S.?

The black-and-yellow arachnids are making headlines again, but scientists say not to be alarmed.

Joro spiders are in the news again, and judging by the headlines, everyone is doomed.

“Giant venomous flying spiders… heading to New York area,” says CBS News . “East Coast braces for invasion of palm-sized venomous spiders capable of flying,” echoes Fox Weather . And The Guardian calls the arachnids “gag-inducing ."

Of course, the scientists who study these animals, which are native to Asia, say such descriptions are misleading at best.

Floyd Shockley , an entomologist and collections manager at the Smithsonian National Museum of Natural History in Washington, D.C., says he’s “mortified” by some of the sensationalist headlines. “There’s no evidence that they’ve made it to New York.”

While it’s true that joro spiders arrived in Georgia in 2014 by unknown means and can survive in the United States, their colonization of the continent isn't exactly imminent. So far, the spiders have been seen in Georgia, the Carolinas, Tennessee, and Oklahoma, with a few tiny satellite populations in places such as Maryland.

What’s more, threat posed by the black-and-yellow arachnids has been routinely exaggerated. (See beautiful photos of spiders.)

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For instance, a recent Gothamist article describes the spiders as having “a body about four inches long and legs that span six to eight inches—about the size of a human hand.”  

“That is completely ridiculous,” says Shockley. “You’d have to stretch this thing out like a medieval torture device to get [its legs] even four inches, let alone six inches.”

What’s more, at this time of the year, every joro spider in the U.S. is no larger than a grain of rice. Adults die each winter, with eggs hatching in the spring and starting the cycle anew.

With so much misinformation afoot, let’s take a look at some of the other claims circulating online.

Can joro spiders fly?

“The way those headlines are written, it makes it sound like they’re the monkeys in the Wizard of Oz,” says David Coyle an assistant professor and invasive species expert at Clemson University.

In truth, none of the large adult joro often pictured in news stories are capable of flight. However, as spiderlings, joro and many other spiders can take to the skies in a common dispersal process called ballooning.

“Right after they hatch, the little hatchlings may be the size of a sesame seed,” says Coyle. “Some of them will get up high and they’ll raise their abdomen. They’ll put a few strands of silk out, and some of them will get carried away by the wind.”  

Yes, just like in Charlotte’s Web . (Related: “This spider web is strong enough for a bird to sit on, a scientific first” )

“I hate to tell people, but every spring, there’s probably thousands of little spiders ballooning over your head, and people have no idea it’s happening.”

As for their "flying" to new states, Shockley says "they have expanded their range, but it's not surprising for an introduced species in 10 years to have moved, you know, a state."

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He adds "we still don't really know anything about how they would [survive] northeastern winters, because obviously they're not there yet."  

Are joro spiders venomous?

This is actually a bit of a trick question, since "spiders are predators and use venom to capture their prey,” says Shockley.

This means that nearly every spider on Earth is venomous, save for two small spider families that have lost the ability to produce venom .

The real question is whether an animal is venomous in a way that could harm people. For U.S. spiders, that is an incredibly small category that includes black widows and brown recluses—not joros, whose venom is non-toxic to people, he says.  

In fact, the few reports of joros biting people suggest it’s like something between the itchy irritation of a mosquito bite and the pain of a bee sting.  

Are joro spiders aggressive?

Despite being relatively large and brightly colored, the joro spider is kind of a pushover.

“Based on my research, they’re really shy,” says Andy Davis , a research scientist at the University of Georgia. “If you leave them alone, they’ll leave you alone, and you can both go about your business.”  

In a 2023 study published in the journal Arthropoda , Davis found that when threatened with a puff of air, native spiders froze for about 96 seconds before resuming their spiderly duties.  

Joro spiders, on the other hand, didn’t move again for more than an hour, making them the most timid arachnids on record. (Read more: “Turns out that huge spider invading the U.S. is incredibly ... shy?” )

“I have held joro spiders dozens of times,” adds Coyle, who has never been bitten. “My kids have held them. They’re typically very docile.”

"They’re just big and scary-looking to a lot of people, but that doesn’t necessarily mean they’re mean or have malevolent or malicious intent.”

The truth about joro spiders  

However unwelcome joro spiders are in the U.S., some experts say it’s time to get used to their new neighbors.

“This is a tough sell,” says Davis, “but maybe, instead of trying to do away with them, people should just maybe sort of learn to live with them. Because their spread is exponential at this point. Like, there’s millions upon millions of them.”

As far as their impact to the environment, it's likely a mixed bag. Joros eat other invasive species, including brown marmorated stink bugs and spotted lanternflies . However, there's also evidence they're outcompeting native spider species .

Even so, Coyle doesn’t see much reason to kill them on sight.

“If it sparks joy, smash them,” he says. “Are you going to do any measurable impact whatsoever to the population? No, you’re not.”

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• HUMAN-WILDLIFE CONFLICT
• SOCIAL MEDIA

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November 4, 2023

This article has been reviewed according to Science X's editorial process and policies . Editors have highlighted the following attributes while ensuring the content's credibility:

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Huge spiders in Eastern US aren't going away, experts say

by Olivia Lloyd, The Charlotte Observer

Since their arrival in Georgia nearly 10 years ago, the yellow-banded Joro spiders and their huge webs have set up camp in the southeastern U.S., experts say.

A new study from Clemson University indicates they're "here to stay." But they're harmless to humans.

The spiders were discovered in Georgia in 2014 and have taken root in the U.S., according to an Oct. 12 release from the university.

The creatures travel via a unique mechanism called "ballooning," according to Penn State University. They use gossamer threads to catch the wind and sail on air currents to a new location.

Researchers say their bodies can grow about an inch long, with their legs spanning up to four inches. The females are larger and brighter in color than the males.

The spiders' spread

David Coyle, a professor of forest health and invasive species at Clemson, said he's seen the population of Joro spiders on his South Carolina property "explode" over the last few years, according to the release.

Coyle worked on the study with other researchers, using 20 variables to model how the Joro spider would fare in the U.S. given its typical native habitat in East Asia.

"Those data show that this spider is going to be able to inhabit most of the eastern U.S.," Coyle said in the release. "It shows that their comfort area in their native range matches up very well with much of North America."

Their current range spans over 46,000 square miles in states including Georgia, South Carolina, North Carolina and Tennessee, according to the release.

Joros have also been reported in Alabama, Maryland, Oklahoma and West Virginia.

Another study has shown the Joro spider to be more cold resistant than its relative, the golden silk spider, allowing Joros to spread farther north.

University of Georgia entomologist Will Hudson also began investigating the spiders after seeing them in his yard.

"Last year, there were dozens of spiders, and they began to be something of a nuisance when I was doing yard work," Hudson said in 2021. "This year, I have several hundred, and they actually make the place look spooky with all the messy webs—like a scene out of 'Arachnophobia.'"

Despite their size and abilities to soar through the air, Joro spiders don't hurt people. In one study, UGA scientists even found they are pretty shy.

"Yes they can look big, and yes some people are quite afraid of spiders, but the reality is there's really no dangers these pose to people or pets," Coyle said.

Researchers are still working to understand the spiders' impact. Coyle said they can look at metrics such as whether other varieties of spiders are less common in areas where Joro spiders are found.

"I think people need to make peace with Joros and accept the spiders because they are not going anywhere," Richard Hoebeke, who first identified the spiders in 2014, told UGA.

For now, the spiders don't appear to have an adverse impact on native species , UGA reported. And you don't have to kill the spider if you see it.

If you see a spider and you don't want it there, Coyle recommends just getting a broom and moving it.

2023 The Charlotte Observer. Distributed by Tribune Content Agency, LLC.

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