False Black Widow Steatoda grossa (C. L. Koch, 1838)Non-native    Synonyms: Teutana grossa, Teutana grossa.
Kingdom Animalia   >   Phylum Arthropoda   >   Class Arachnida   >   Order Araneae   >   Family Theridiidae   >   Genus Steatoda   


Cosmopolitan species that was introduced to North America from Europe. Considered harmless to humans and in fact sometimes known to prey upon black widows!


Note oval abdomen versus the teardrop-shaped abdomen of true widows. Can have light spots and bands, but often all black, always lack hourglass marks.

Where to find:

Cosmopolitan species found around homes and buildings. This species is considered harmless.


Feeds on a wide variety of arthropods, especially pillbugs. Known to prey upon black widows.

There are 7 records in the project database.

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A False Black Widow in Anne Arundel Co., Maryland (9/16/2012). Introduced from Europe and found near human habitations on both coasts and along the Great Lakes. Note similar shape, complete lack of red markings, and subtle structural details. Photo by Bill Hubick. (MBP list)

A False Black Widow in Queen Anne's Co., Maryland (5/6/2015). Photo by Lori Byrne. (MBP list)

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