Latrodectus mactans

Latrodectus mactans, commonly known as the Southern black widow or simply the black widow, is a species of highly venomous spider in the genus Latrodectus. They are well-known for the distinctive black and red coloring of the females and for the fact that they will occasionally eat their mate after reproduction, a behavior from which their common name is derived.

Description

The adult female black widow has a shiny black body, slender black legs, and a red or red-orange hourglass-shaped mark on the underside of the abdomen. Some may also have a series of red spots along the top center of the abdomen. Adult males are half the size of females, and are gray or brown rather than black. They have light streaks on their abdomens, and their hourglass marking is less defined. Juveniles have a more camouflaged brown and white appearance.

Distribution and habitat

The Southern black widow is native to North America. The species is found in the southern states of the United States, including Florida, the Carolinas, and Texas. They are also found in parts of Mexico and the West Indies. They prefer warm climates and are commonly found in dark, undisturbed sites, such as among rocks, woodpiles, or in the corners of garages or outbuildings.

Behavior and ecology

Black widows are solitary spiders, interacting with others only for mating. They are nocturnal, coming out at night to feed on insects, other spiders, and small vertebrates. The female produces a strong silk to create a web, which she uses to capture her prey.

Venom

The venom of the Southern black widow is a neurotoxin that can cause severe systemic reactions in humans. Symptoms of a black widow bite can include pain, muscle rigidity, vomiting, and sweating. Despite the severity of symptoms, deaths from black widow bites are rare, thanks to the availability of antivenom and the relatively small amount of venom the spider typically injects.

See also

• Latrodectus hesperus
• Latrodectus geometricus
• Spider bite