Guinness lists Phoneutria as the most venomous spider on Earth — toxicity measured per microgram of venom.
AgencyGuinness World RecordsShare →
Brazilian Wandering Spider
Phoneutria nigriventer
World's most venomous spider. Doesn't build webs — wanders. Found in shoes, banana shipments.
Curated and rated by Sheriff Six-Legs and The Wild Pest field team · Six Legs Score™ (87/100, Outlaw tier) · Published Apr 25, 2026 · Updated Apr 28, 2026 · Released CC BY 4.0
87Six Legs
Six Legs Score™
87 / 100
The Guinness Book of World Records lists the Brazilian wandering spider as the most venomous spider on Earth. Doesn't build a web — wanders the forest floor at night hunting prey, often hiding in shoes, banana bunches, and grocery shipments. The venom contains a peptide (PnTx2-6) currently in clinical trials as a treatment for erectile dysfunction.
Size
Body 3-5 cm; leg span 13-18 cm
Lifespan
1-2 years
Range
Central and South America (tropical)
Diet
Insects, lizards, small mammals, other spiders
Found in
Forest floor, banana plantations, occasionally inside human dwellings
Field guide
Phoneutria nigriventer is one of eight species of Brazilian wandering spider, all found in tropical Central and South America. Guinness lists this genus as the most venomous spider on Earth based on toxicity per microgram of venom. Unlike most spiders, Phoneutria does not build a permanent web — she wanders the forest floor at night hunting prey, returning by day to hide in dark crevices, leaf piles, and (notoriously) inside shoes, banana bunches, and exported produce. Banana-shipment incidents bring Phoneutria spiders to grocery stores in Europe, North America, and Asia hundreds of times each year. The venom contains a complex cocktail dominated by PhTx (Phoneutria neurotoxins) targeting sodium and calcium channels. One peptide, PnTx2-6, has been in clinical trials since 2010 as a potential treatment for erectile dysfunction (it produces sustained, painful erections as a side effect of envenomation). Brazilian antivenom (developed 1925) has reduced mortality to under 0.5% of bites; over 4,000 bites are reported annually in Brazil.
5 wild facts on file
Brazilian wandering spiders don't build webs — they walk the forest floor at night hunting prey.
EncyclopediaEncyclopedia of LifeShare →
Banana-shipment incidents bring wandering spiders to grocery stores in Europe and North America hundreds of times each year.
AgencyInternational Society of ToxinologyShare →
A peptide from wandering spider venom (PnTx2-6) is in clinical trials as a treatment for erectile dysfunction.
JournalJournal of Sexual Medicine — Nunes et al. (2010)2010Share →
Brazilian antivenom developed in 1925 has reduced wandering-spider bite mortality to under 0.5% of cases.
AgencyBrazilian Ministry of Health1925Share →
Cultural file
Banana-shipment incidents involving wandering spiders are tracked by major supermarket chains as a logistics-safety issue — Lidl, Asda, and Tesco have all closed stores temporarily after spiders were found. The incidents drive periodic public-fear cycles in tabloid press. The venom-derived ED drug research has produced over 50 academic papers since 2010.
Sources
AgencyGuinness World Records — Most Venomous SpiderJournalNunes et al. (2010). Journal of Sexual Medicine2010
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