False Black Widow

Scientific Name: Steatoda grossa

Order & Family: Order Araneae, Family Theridiidae

Size: Adult females: 6-10.5 mm in body length; males: 4-6 mm.

False Black Widow

Natural Habitat

Commonly found in and around buildings, garages, sheds, and gardens, often in dark corners and crevices.

Diet & Feeding

Carnivorous; feeds on a variety of crawling and flying insects, as well as other spiders caught in its messy cobwebs.

Behavior Patterns

Nighttime hunters that build irregular, tangled webs. They are timid and usually retreat into a crevice when disturbed. Life cycle typically spans 1 to 6 years.

Risks & Benefits

Beneficial as natural pest control. While biters are rare and usually occur when the spider is squeezed, the venom can cause localized pain, blistering, or 'steatodism' (mild flu-like symptoms), but is not considered medically significant for healthy adults.

Identified on: 5/20/2026