Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada

Species Steatoda grossa - False Black Widow

Saw several of these in my garage yesterday, can anyone tell me what it is? - Steatoda grossa Spider Repeat - Steatoda grossa Garage door spider needs ID - Steatoda grossa Steatoda Triangulosa - Steatoda grossa Steatoda sp. - Steatoda grossa spider - Steatoda grossa Unknown Spider 4 - Steatoda grossa Spider I found in my chameleon enclosure - Steatoda grossa
Classification
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Chelicerata (Chelicerates)
Class Arachnida (Arachnids)
Order Araneae (Spiders)
Infraorder Araneomorphae (True Spiders)
No Taxon (Entelegynae)
Family Theridiidae (Cobweb Spiders)
Genus Steatoda
Species grossa (False Black Widow)
Synonyms and other taxonomic changes
Teutana grossa
Identification


Some diagnostic drawings:

General habitus


Male palp:


Female epigyne:


Eye arrangement (male):
Range
Imported from Europe; In North America it has now been found in states along the east and west coasts as well as those bordering the Great Lakes. Specimens have also been collected in Colorado. It's also considered a cosmopolitan species and is found in other countries all over the world.
Habitat
In and around homes and buildings.
Season
Males mature in summer and autumn; adult females can be found year-round.
Food
Any arthropods that are snagged in the cobweb. This species is a specialist on pill bugs and real black widow spiders.
Life Cycle
Female Life Cycle:

Remarks
The bite of this spider might produce symptoms that are similar but much less severe than those of a black widow bite. In some cases blistering may form at the site of the bite along with physical discomfort that lasts for several days.
Internet References
Auburn.edu - range.
www.ipm.ucdavis.edu - How to Manage Pests of Homes, Structures, People, and Pets by R. S. Vetter