Southern Black Widow

The southern black widow, Latrodectus mactans, is a member of the widow spider genus and is found across the southern and eastern United States, extending into parts of Mexico. Females are instantly recognizable by their glossy, globular black abdomen marked underneath with a red or orange hourglass-shaped marking, one of the most iconic warning patterns among North American spiders. Males and juveniles look quite different, being smaller and patterned with lighter tan, brown, and white markings rather than solid black.

Southern black widows are shy, sedentary spiders that build an irregular, tangled cobweb in dark, undisturbed locations close to the ground, such as woodpiles, sheds, crawl spaces, and debris piles. They rarely leave the immediate vicinity of their web and are far more likely to retreat than to confront anything approaching.

As with other widow spiders, the southern black widow is a predator within its habitat, feeding on a variety of insects and other small arthropods that become entangled in its web, and it is best identified by its glossy black coloration and red hourglass marking together with its cobweb-building habit.

• Glossy black, rounded, bulbous abdomen on adult females
• Red or orange hourglass-shaped marking on the underside of the abdomen, sometimes broken into two separate triangles
• Long, thin legs relative to the compact body
• Males and juveniles are smaller, lighter in color, and patterned with tan, brown, and white markings rather than solid black
• Builds an irregular, tangled cobweb close to the ground in dark, sheltered locations rather than an open orb web
• Lookalikes include the closely related northern and western black widow species, distinguished mainly by subtle differences in the hourglass marking's shape and completeness

Southern black widows favor dark, undisturbed, sheltered spaces close to the ground, including woodpiles, sheds, garages, crawl spaces, meter boxes, and debris piles. They are found throughout the southern and eastern United States, from the Atlantic coast to Texas, and south into parts of Mexico, generally in warm temperate to subtropical climates.

This species builds a messy, three-dimensional cobweb near ground level, often anchored between debris or structural gaps, with sticky trap lines extending down to intercept crawling insects. The spider remains within or near a small silken retreat in the web, rushing out to subdue prey caught in the sticky threads before wrapping and feeding on it. Southern black widows are not aggressive and are reluctant to leave their web, generally retreating deeper into the tangle when disturbed rather than confronting a threat. As predators, they help regulate populations of insects and other small arthropods within the sheltered habitats they occupy.

Females produce several round, papery, tan-colored egg sacs over the course of a season, each containing large numbers of eggs, and often guard them within the web. Spiderlings hatch and disperse widely, sometimes ballooning on silk to new locations, and go through numerous molts as they grow, with juveniles displaying lighter, patterned coloration that darkens toward solid black as they approach maturity. Development speed depends on climate and food availability, with adult females capable of living a year or more and producing multiple egg sacs across that time, while males have a considerably shorter adult lifespan.