Physical Characteristics

Like the black widow (Latrodectus hesperusL. mactans), the body of the female adult brown widow spider – also known as the gray widow spider and geometric button spider – is about 1/2 inch long, with long, banded (tiger-striped) legs, and a geometric pattern on its back. Females typically are light to medium brown in color, although they may range from almost white to gray to almost black, with an identifiable marking of an orange or yellowish hourglass. Males are about half that size, with longer legs than L. Hesperus males. Egg sacs are easily identifiable – tan, spherical, with spiky protrusions, not unlike World War II sea mines.

brown widow

Brown widow spider

Behavior

L. geometricus is a recent transplant from southern Africa; it’s a tropical spider that has spread throughout the American southeast, specifically the Gulf Coast. So far in California, it’s been found from San Diego County in the south to Los Angeles County in the north, and as far east as Riverside County. Of all the Latrodectus species, brown widows are the most prolific breeders; one female can bear 5,000 young spiders per season. Brown widow spiders weave messy webs that can be found in lots of places around buildings and gardens. Favorite harborages include plastic lawn chairs, plastic flower pots and bird-of-paradise plant leaves – anywhere sheltered that offers hiding. It’s the females that bite, but brown widows reportedly are far more timid than their black widow cousins. Bites are rarely fatal. If you are bitten, call a physician or visit an emergency room right away. 

Latin Name: Latrodectus geometricus