The Brazilian wandering spider is the commonly used generic term for what is in fact a family of eight different species, found in the rainforests of the Americas all the way from Costa Rica to Argentina, including Peru.
Also known as the “armed” or “banana” spider (for its alarming habit of finding its way into shipments of bananas), this fearsome creature is called the “wandering spider” because instead of building a web and laying in wait for its prey, species of the Phoneutria genus prefer to go in search of their victims.
Phoneutria means “murderess” in Greek, and these spiders certainly live up to their reputation as the deadliest arachnids in the world. The best known member of the Phoneutria genus is Phoneutria nigriventer, because it is frequently found near human settlements and is therefore the species of wandering spider which most often comes into contact with people. Along with Phoneutria fera, this is the species most closely associated with the widely used common name “Brazilian wandering spider”. Two other species of the genus Phoneutria live in the rainforests of Peru’s Tambopata National Reserve.
While the Brazilian wandering spider has even been included in the Guinness Book of World Records as the “world’s most venomous spider”, very few substantiated reports have been received of it biting humans; however, its venom certainly has the potential to kill a human, particularly a child, where no venom antiserum is available for timely treatment of the victim.
The venom of the deadliest species of the Phoneutria genus has been reported as being more lethal than that of the famous black widow spider. They are nocturnal and tend to feed on mice, small lizards, frogs and large insects, and are able to kill such manageable prey with a single bite.
As mentioned, wandering spiders are also known as “banana spiders”. One particularly famous case of these venomous stowaways making it to more northerly climes was widely reported in the British press, when in 2005 a man was bitten in the UK and as a result was hospitalized for several weeks.
Wandering spiders are very large, with some species reported as possessing bodies around five centimeters (two inches) in diameter, and legs up to fifteen centimeters (six inches) long. Their brown tones vary across the eight known species, although all of them are reported as being hairy. In common with other spider species, the female wandering spider is larger than the male, and will often attack and even kill her partner following copulation.
A single fact concerning the bite of the wandering spider is probably most responsible for the intimidating reputation they possess. By working to increase blood flow in victims and disrupt their neuromuscular systems, in addition to cramps, abdominal pain, convulsions and severe burning pain, the chemicals in these spiders’ venom can cause prolonged and painful erections in male humans, and scientists have been researching ways of using wandering spider venom in treatment for erectile dysfunction.