The Legend of the World’s Most Venomous Spider: the Phoneutria

Since living in Panama, I have become aware of the many different species of both animals and plants that can do anything from make me blind within a few hours to straight up kill me. One of which is the highly venomous banana spider/wandering spider (Phoneutria), which seems to call the staff living quarters home as well. This blurry photo is of one I removed just last week. Removed= rereleased outside. No spiders are ever hurt or destroyed.


The Phoneutria spiders are large spiders and easily reach the size of a grown man’s hand. They are commonly called the banana spider because they can often be found hiding in banana leaves. The Phoneutria gained public awareness in England 2005 when Mathew Stevens, a pub chef, was bitten by a Phoneutria that had been hidden in a delivered box of bananas. The BBC News reported Mr. Stevens “took nearly a week to recover from the bite following treatment at Musgrove Park Hospital in Tauton.” Their second given name is the wandering spider. This is because they often wander the jungle floor at night, so biologists who perform research at this time know to be careful.

I have personally removed (with some help) about 5 of these spiders, one of which had fallen on my hand when I reached for a pineapple in the kitchen. Needless to say, I may have let out an unprofessional little scream. So, I’ve decided that its time to figure out the truth behind these large spiders that seem to be quite common in the Western lowlands of Panama. Are they, in fact, the most venomous spider in the world? Could they actually kill a person?

A phoneutria we found in the laundry room

A phoneutria we found in the laundry room

The current Guinness World Book of Records states “the world’s most venomous spiders are the Brazilian wandering spiders of the genus Phoneutria, and particularly the Brazilian huntsman Pheoneuria fera.” Thankfully, this is not the same species that is found in Panama, however, our Phoneutria boliviensis is still a Phoneutria.

But as a genius, why are they so dangerous? According to the Staatliches Museum für Naturkunde Karlsruhe, the answer lies in their specific type of venom, which contain neurotoxins that act on the ion channels and chemical receptors in the brain. This can cause loss of muscle control, breathing problems and eventually asphyxiation. Another interesting side effect is a quite uncomfortable erection. In fact, according to Romulo Leite of the Medical College of Georgia,, as reported on by Jeanna Bryer “the erection is a side effect that everybody who gets stung by this spider will experience…” Well, I guess except for us females.

Although according to a few websites (Note: I couldn’t find any scientific articles on this), the species commonly found in Western Panama, Phoneutria boliviensis, is not the most venomous species of Phoneutria, however, I really don’t want to test this out.

A wandering phoneutria I stumbled upon during a night hike

A wandering phoneutria I stumbled upon during a night hike

However, most of the dangers with this kind of spider are due to the fact that they come in close contact with human establishments since their natural habitats (the jungles) are being cut down. Only a small number of deaths are reported each year and they normally involve either children or the elderly (similar to common viruses). I recommend just being aware and remembering to shake out your clothes and check your shoes before you put them on. And keep in mind, they are not out to get you, they’re just trying to be a spider.

Safe travels! ~B

14 thoughts on “The Legend of the World’s Most Venomous Spider: the Phoneutria

  1. Yes there are lots of them, we had an arachnologist stay with us from bocas del toro, who taught us a grest deal, as you can imagine we had no idea what was there when we first arrived.there are spiders like the brown recluse which often come in the house, have you been stung by the scorpions yet? They are quitenice, a bit like an anesthetic, i got done in the face, arm, and hand, the last time I was playing with it.there is a nettle tree up at the top of the property which is very painful, big leaves with hairs, I had an extremely dangerous one as a specimen but Michelle made get rid of was so painful even when it was a seedling.keep an eye out for a hairyy plant on the corner of the lounge.pull it out carefuly if you see it.

    • I haven’t seen any brown recluse yet (thankfully!). I haven’t been stung by any scorpions yet (also thankfully), but I’ve seen quite a few. The craziest was this female scorpion that had about 100 baby scorpions on her back. That will forever haunt me/be the coolest thing ever. Does this hairy plant look similar to a tomato plant when its a seedling? There is something like that everywhere and I can’t figure out what it is.

  2. Hello and Greetings from the poisonous spider/scorpion safe Stockholm,Sweden 🙂
    Is there anyone who might know where to buy a dead, dried speciement of this phoneutria boliviensis in your country? I have started to collect tropical spiders for molding them in lucide (sort of plastic material), but I have difficulties to buy one of these here in Europe. Looking forward any answer.

    • Honestly it might just be easiest to ask a local for one. Certain times a year they are literally EVERYWHERE. So it would be easy to find a dead one. We actually had a huge one get stuck in the heater- eeekk! Anyways, I hope that helps! Don’t know of any specific retailers or shops that carry them though. Best of luck!

  3. bit of an odd question regarding this … when the spiders are coming over with the bananas, would they ever bite and therefore inject the bananas with their poison? out of fear i mean, not because their hungry. After suffering a mildly serious reaction after eating a banana, i returned home to find what i believe to be one of these crawling up my curtain. the reaction/timings/description all sound correct.
    unfortunately my housemate killed it with a shoe. i have a bad vid and picture, but we were so freaked out that we kinda wrapped it in a tissue and threw it out. no lawsuit unfortunately. any info medicalwise would be helpful 🙂

    • Haha not that I’ve heard of! The spiders seem (in my limited spider knowledge) to be able to tell the difference between prey and banana 🙂 Medical-wise, if you have proper health care available you will most likely be just fine. The scary stories usually occur in places where it takes hours to reach an emergency room. Hope that helps and way to be brave!!

  4. I used to live in El valle De Anton, Panama And the spiders there were the biggest I’ve ever seen. They we’re everywhere. And that made life hard for me being that I’m an extreme arachnophobe. Other than that I loved living there. Beautiful country.

  5. Oh, girls. My husband wants to move the fam to central America. I am adventurous and love to travel, but I cannot handle spiders! We are headed to Bocas del Toro staying in a lovely “tree house” like rental (vacation) which seemed really romantic to me until I read this. I don’t want to lose my sense of adventure and fun, so what can a girl do to sleep at night knowing these critters are there?

    • I would just check any dark areas around the house before heading to bed- A solid broom and a flashlight goes a long way for this task. But honestly, they aren’t going to “come after you.” Most importantly, there doesn’t seem to be a lot of these spiders around Bocas, so you should be totally fine. They seem to prefer a more arid/forest environment. Have an amazing trip!!!

  6. Hi. quick comment from another arachnologist. Firstly, i’m betting that one who visited Bocas was an awesome scotsman named Ray. Secondly, if you’re writing about wildlife, it’s often really useful data to write when and where something was spotted, i’d like to hear where/when these animals were found. Now then, very nice write-up, rather balanced and informative, unlike almost all popular press! But here’s the kicker, only one of those three spiders photographed is a Phoneutria. The one in the fist image looks much more likely the genus Cupiennius, which are all essentially harmless to humans and some in Panama can look spectacularly like Phoneutria. They’re often rather more timid and flighty though. Similarly, the third seems more like genus Ctenus, really hard to tell species apart for those, often impossible from just a photograph. Again, most of those are deemed harmless to us humans, although the venom of most isn’t properly quantified. Finally, just to add that the venom effects of the species called P.boliviensis is considered far milder in effect than some of the most formidable Southern Brazilian species. And that’s based on some published studies for Costa Rican toxicity. Although i wouldn’t recommend a bite from any, I wouldn’t consider the Central American ones anywhere near as dangerous as the media makes out, and importantly often the spider responsible for the bite gets misidentified, such as these supposedly harmless others shown here.

  7. I was stationed in panam for two years while i was in the military.I did see two scorpons some spiders as big as my hand on webs,but thats about it.They dont mess wth people very often.My friends saw a poisonious snake or two but i never did.Unless you walk through the jungles often you wont have an issue with these creatures.

  8. I have been keeping my eye on a mum.spider since Aug 25, she had her babies lastnight, oct 19. She has the same dots on her back a dthe foto its been like i have a roommate, as she lives on the porch. But now that she has had like 500 babies… OMG what did i get myself into, buy not moving her. Oh shit. Google said they will move out and find their own territory. But in the mean time? Oh my
    Ps. Good write-up

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