Arachnid · GBIF taxon 2157245
False Black Widow
Steatoda grossaAlso known as Cupboard Spider, Dark Comb-Footed Spider, Brown House Spider
False black widows build tangled web scaffolds in dark, humid spaces like basements, sheds, and stone walls. They spend most of their lives hanging upside down waiting for crawling insects or sowbugs to stumble into their sticky tripwires. Females construct spherical beige silk egg sacs, guarding them inside secluded retreats until the spiderlings hatch.
NocturnalWeb-BuildingSynanthropic
—observations
—countries
—peak records
Not EvaluatedConservation statusIUCN Red List categoriesLCNTVUENCREWEXNot Evaluated — not placed on the risk ladderRed List categories, explained →
Diet & prey
- Woodlice
- Cockroaches
- Flies
Predators
- Spitting Spiders
- Centipedes
- Birds
ThreatsPesticides and severe winter cold in extreme northern ranges
HabitatsBasements, crawlspaces, stone walls, sheds, and dark crevices
Life spanUp to 6 years
Size / weightNot available
Classification
- OrderAraneae
- FamilyTheridiidae
- GenusSteatoda
- SpeciesSteatoda grossa
Range data is not available yet.
Interaction riskVery high
- Low
- Moderate
- High
- Very high
- Why interaction risk is very high
- Bites can be painful but are not medically severe; observe without handling directly.
- Why it is dangerous
- Injects venom that can cause localized pain, minor swelling, sweating, and nausea lasting up to several days.
- How to recognize a risky encounter
- Distinguished by a dark chocolate-brown to purplish-black bulbous abdomen that lacks any bright red hourglass marking.
- What to do
- Avoid touching directly with bare hands; use a container and card if relocation is necessary.
Responsible observation
- Observation: Use a small flashlight to view them hanging upside down in dark basement corners.
- Relocation: Place a wide glass over the spider and slide a stiff card beneath to move it outdoors.
Look-Alike (c) Justin Williams, some rights reserved (CC BY), uploaded by Justin Williams · cc-by
Predator 
Close Relative (c) Dustin Edmundson, some rights reserved (CC BY), uploaded by Dustin Edmundson · cc-by
Close Relative (c) Patrick Hacker, some rights reserved (CC BY), uploaded by Patrick Hacker · cc-by
Help improve the field guideSomething wrong?
Checking your Fauna account…Report a name, category, or profile issue for review.