Home » Guide » Arthropods (Arthropoda) » Chelicerates (Chelicerata) » Arachnids (Arachnida) » Spiders (Araneae) » True Spiders (Araneomorphae) » Entelegynae » Cobweb Spiders (Theridiidae) » Steatoda » Steatoda borealis

Species Steatoda borealis

boreal cobweb spider - Steatoda borealis - male

Steatoda borealis? - Steatoda borealis - female

cobweb spider - Steatoda borealis - female

another linyphiid? - Steatoda borealis - male

Black ground spider sp? - Steatoda borealis

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 borealis (Steatoda borealis)

Explanation of Names

Latin for "northern"

Size

Females reaching a maximum size of about 7 mm

Identification

The abdomen is reddish brown with a lighter "T" shaped mark at the front end. The underside of the abdomen is also considerably lighter than the upper side.

Note that several other species in the genus (including bipunctata, grandis, hespera, and possibly mexicana) can have nearly identical markings.

Range

East of the Rocky Mountains in the United States to Alaska. Typically in northern states, but has recently been found in southern ones over the past 50 years or so.

Habitat

Most likely to be found under bark and stones, in rock crevices, on bridges and in outbuildings and unfinished basements.

Life Cycle

Click on the image below to see the life cycle.

Remarks

This species is native to North America.

Both males and females have a rough surface with ridges on the abdomen front that forms a stridulating organ. The spider can make sounds by rubbing this against the carapace. (1)

See Also

Steatoda bipunctata

Internet References

http://www.royalalbertamuseum.ca/natural/insects/bugsfaq/borcob.htm

Works Cited

1.	Common Spiders of North America Richard A. Bradley . 2012. University of California Press .

Contributed by Christopher C Wirth on 15 October, 2005 - 7:39pm
Additional contributions by Lynette Elliott, Chuck Entz, marcie oconnor, Mandy Howe, Marci Hess, chuuuuung
Last updated 20 June, 2024 - 11:37pm

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