Black Widow Spiders

Lactrodectus mactans
Pest Stats
Color: Black, with characteristic red "hourglass" on back
Legs: 8
Shape: Round
Size: 1 ½ - 1 3/8 inches long
Antennae: No
Region: Found throughout U.S.
Download the Black Widow Spider Pest I.D. Card

Black widow spiders are most recognized for the red hourglass shape under their abdomen. This spider gets its name from the popular belief that the female black widow spider eats the male after mating, although this rarely happens. Black widows are poisonous when ingested during the first 17 days of their life.

Habits

Black widows are active when the temperature is 70 degrees or higher, but they can survive lower temperatures with the right conditions. Black widow spiders spin irregular webs, which they build at night near ground level. Once complete, these spiders hang upside-down in their webs.

Habitat

Outdoors, black widow spiders commonly live in protected areas like under stones and in firewood piles. They are often found in barns, outhouses and sheds. Indoors, black widows prefer cluttered areas of garages, basements and crawl spaces.

Threats

While male black widow spiders rarely bite, females are known to be aggressive and bite in defense, especially after laying, and when guarding eggs. Symptoms of a black widow spider bite include fever, increased blood pressure, sweating and nausea. Fatalities are unlikely, as long as proper medical treatment is sought in a timely manner. If you notice black widows or signs of infestation, contact a professional immediately for a proper course of black widow spider control.