Black Widow Spiders

Facts, Identification & Control

Latin Name

Latrodectus spp.

Appearance

Black widows are identified by red hourglass marking on the underside of their abdomens. Black widows are shiny black in color. Females are larger than males and can measure 13 mm in body length. These spiders are members of the genus Latrodectus.

Black Widow Illustration black widow spider

Behavior, Diet & Habits

Black widow spiders favor dark, secluded areas such as crevices and woodpiles. They thrive primarily in temperate zones and are known to be abundant in the American South.

Several species of Latrodectus or “widow” spiders are present in North America. The most common are: the southern widow (Latrodectus mactans) found in the American South and Northeast; Latrodectus hesperus found in the west; the brown widow (Latrodectus geometricus) found in the South; and the northern widow (Latrodectus variolus) found in the Northeast.

Signs of a Black Widow Infestation

Black widows produce messy, irregular webs. Webs usually are located near ground level and under a protected ledge such as under lawn furniture or wood piles. The female with the iconic red hourglass marking also indicates their presence.

More Information

Contrary to popular belief, spiders are not insects; rather, they are arachnids. Being arachnids, they have two body segments, eight legs and do not have wings or antennae.

Most black widow spiders’ bodies are 3 to 10 mm in size. They live an average of one year, although some species may survive for up to three years. These spiders live longest in captivity. Black widows are the largest of web-spinning spiders.

Black widow spider females earned their name for rumor that they kill and eat males after mating. This behavior does occur, as it often does in many spider species. However, the males are not always eaten and often survive to mate again.

The black widow contributes to the balance of the ecosystem by consuming insects such as flies and mosquitoes. It also controls crop pest populations, feeding on pests that defoliate plants, including locusts, grasshoppers, beetles and caterpillars.

black widow spider closeup