Southern Black Widow

• Its venom is up to 15 times more potent than a rattlesnake's, though the dose delivered is rarely fatal to a healthy adult.
• The male courts the female by plucking the threads of her web to identify himself before mating.
• It catches insects and small arthropods that become tangled in its irregular web.
• reproducciónFemales may eat the male after mating, though this happens less often in the wild than in captivity.
• Its venom contains alpha-latrotoxin, which triggers a massive release of neurotransmitters at the nerve endings. The result is latrodectism: intense muscle spasms, abdominal rigidity, sweating and generalised pain.
• The bite is barely felt: it is described as a slight pinprick, and the serious symptoms appear between half an hour and several hours later.
• The abdominal pain can be so intense and the rigidity so marked that it has been mistaken for a surgical acute abdomen.
• Antivenom has existed since 1936, and deaths today are exceedingly rare.
• The red hourglass on the belly is its trademark, but only the female has it; the male is far smaller and practically harmless, because his chelicerae can barely pierce the skin.
• The sexual cannibalism that gives it its name is real but the exception under natural conditions, and considerably less frequent than in the Australian redback spider.

Skeleton type

Invertebrate - chitin exoskeleton

Habitat & environment

Warm and temperate parts of south-eastern North America and Central America, in crevices, burrows and dark corners of buildings

Birth weight

Tiny on hatching, whitish and darkening with each moult

Size at birth

Tiny and pale on hatching from the egg

Sexual maturity

Female: ~90-140 days after hatching | Male: ~54-88 days

Gestation / incubation

~20-30 days of egg development

Litter / clutch size

Hundreds of eggs per egg sac (25 to 900 depending on the source), with several sacs a season

Lifespan in captivity

Documented record of up to 3-4 years in captivity

Sources consulted: Connecticut Agricultural Experiment Station; Animal Diversity Web; iNaturalist; LiveScience; Oklahoma Dept. of Wildlife Conservation; Exotics Source; Oklahoma State University Extension