Steatoda grossa
(False Black Widow)

Taxonomic Hierarchy

  • Kingdom: Animalia
  • Phylum: Arthropoda
  • Class: Arachnida
  • Order: Araneae
  • Suborder: Araneomorphae
  • Family: Theridiidae
  • Genus: Steatoda
  • Species: Steatoda grossa

Common Name (AASMore information icon)

False Black Widow

Other Common Names

Cupboard Spider, False Button Spider, Cobweb Spider, Cob Web Spider, Comb-footed Spider, Tangle-web Spider, Gumfoot-web Spider

Author

Carl Ludwig Koch, 1838

Pronunciation

stee-uh-TOH-duh GROW-sah

Identification Traits

Disclaimer: The following table provides a quick overview of the spider's basic attributes. The physical traits are greatly generalized in order to aid in the identification and sorting of spider species using our search feature. This information is not exhaustive, and keep in mind that traits such as color, markings, and overall size and shape can vary widely within a species due to variables such as the spider's age, gender, diet, hydration level, climate, and habitat. Though experienced arachnologists and hobbyists can often classify spiders rather accurately based on their unique markings and general appearance, it's important to know that scientifically accurate spider identification relies on detailed taxonomic keys and microscopic examinations of a spider's reproductive organs.

Female iconFemale Male iconMale
Body size More information icon 6mm - 11mm 4mm - 9mm
Eye count 8
Primary Colors
Identifying Traits Smooth or shiny appearance, Spherical body, Unique pattern, Patternless, Legs solid color
Web style Cobweb


Additional Remarks

  • This species is frequently mistaken for a real “black widow” of the genus Latrodectus. Real “black widows” have a bright red or orange hourglass-shaped marking on the underside of their abdomen, but Steatoda (the “false widows”) do not.
  • Egg sacs are completely different from those of the real “black widows.” Steatoda sacs are made of fluffy-looking white silk; Latrodectus makes papery-looking brown or tan sacs.
  • Females are variable in color and pattern depending on their age. Older adult specimens often lose their abdominal pattern and appear solid black, brown, or purplish; younger specimens have a unique pattern with a pale band across front of abdomen and additional pale spots or chevrons behind.
  • Timid and non-aggressive species.
  • Lateral eyes are nearly touching. (As opposed to the real “black widows,” whose lateral eyes are separated.)
  • Typically only visible in their web at nighttime; spends the day hiding in crevices or holes on outskirts of web.
  • Has been known to feed on real “black widows” (genus Latrodectus).

Featured Pictures

Picture of Steatoda grossa (False Black Widow) - Dorsal Enlarge picture icon
1
Picture of Steatoda grossa (False Black Widow) - Male - Dorsal Enlarge picture icon
2
Picture of Steatoda grossa (False Black Widow) - Dorsal Enlarge picture icon
3
Picture of Steatoda grossa (False Black Widow) - Female - Dorsal Enlarge picture icon
4
Picture of Steatoda grossa (False Black Widow) - Female - Ventral Enlarge picture icon
5
Picture of Steatoda grossa (False Black Widow) - Female - Dorsal Enlarge picture icon
6
Picture of Steatoda grossa (False Black Widow) - Female - Egg Sacs Enlarge picture icon
7
Picture of Steatoda grossa (False Black Widow) - Female - Lateral Enlarge picture icon
8
View All Pictures


Similar Species