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False Black Widow

Steatoda grossa

CommonInsect & Arthropod
Illustration of False Black Widow (Steatoda grossa)

The False Black Widow is a medium-sized dark brown spider with a round abdomen that resembles the black widow but lacks the hourglass marking. Its bite is mildly venomous — producing localized pain but rarely serious symptoms — and it is often misidentified as a black widow. It builds tangled webs in dark corners, basements, and garages and can coexist with humans.

Habitat
Buildings, garages, basements, and dark sheltered spaces
Diet
Adults: insects and other arthropods caught in tangled webs
How common
Common

Best time to see a False Black Widow

The best time to see a False Black Widow is March–September, when about 60% of U.S. sightings happen, based on 9,382 research-grade iNaturalist observations.

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