Bug Identifier
False Widow Spider
Community identification

False Widow Spider

Steatoda grossa

Order & Family
Araneae, Theridiidae
Size
Females typically 6-10 mm; males 4-6 mm (body length). Excluding leg span.
See this bug in the Encyclopedia

Natural Habitat

Commonly found in and around human dwellings, basements, sheds, garages, and other undisturbed sheltered places. They often build irregular, tangled webs in corners or under objects.

Diet & Feeding

Mainly feeds on other small insects and arthropods, which they catch in their webs. This includes flies, mosquitoes, woodlice, and sometimes other spiders.

Behavior Patterns

Nocturnal hunters, resting during the day. They construct irregular, sheet-like webs. Females are known to be reclusive and territorial. They are generally not aggressive but will bite if provoked or trapped.

Risks & Benefits

Potential Risks: While not considered medically significant like black widows, their bite can cause symptoms such as localized pain, swelling, and redness, which usually subside within a few hours to a few days. Systemic effects are rare but can include nausea, headache, and lethargy. Potential Benefits: They help control populations of various household pests, such as flies and other insects.