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Family Theridiidae - Cobweb Spiders

Tidarren sisyphoides? - Tidarren sisyphoides Black house spider Hello, pretty. - Steatoda Elusive spider - Steatoda grossa - male Theridiid by my window - Tidarren sisyphoides - female Is this a freshly molted Parasteatoda tepidariorum? - Parasteatoda tabulata cobweb spider - Asagena medialis Episinus - Episinus amoenus
Classification
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Chelicerata (Chelicerates)
Class Arachnida (Arachnids)
Order Araneae (Spiders)
Infraorder Araneomorphae (True Spiders)
No Taxon (Entelegynes )
Family Theridiidae (Cobweb Spiders)
Other Common Names
Comb-Footed Spiders
Numbers
234 spp. in 32 genera in our area (over 2200 spp. in 96 genera worldwide) (1)
Identification

In separating Theridiidae from Linyphiidae (1)
1. Legs
    Theridiidae have first legs usually longest, third legs shortest. Also fourth legs usually with comb macrosetae (indistinct in Dipoena & Euryopis). Legs have no thick setae and no femoral macrosetae.
    Linyphiidae have legs long & thin with macrosetae. (Hairs on males somewhat reduced.) They have long sensory hairs on the first three legs, sometimes on all four legs.

2. Abdomen
    Theridiidae have abdomen usually round, rarely elongate.
    Linyphiidae abdomen usually oval or elongated.
Remarks
family may not be a monophyletic group
genera Achaearanea, Anelosimus, and Theridion are known to contain subsocial species, but the only social spiders in our area are in the genus Anelosimus

Spiders with very small (if strong) jaws (such as crab spiders and cobweb weavers) make small holes in the prey and vomit their digestive fluid into the prey's body, the end result being a hollow shell with some or most of the muscles and internal organs digested and sucked out. (2)
Print References
Levi 1957(3)
Works Cited
1.Spiders of North America: An Identification Manual
D. Ubick, P. Paquin, P.E. Cushing and V. Roth (eds). 2005. American Arachnological Society.
2.The Spider Myths Site
3.The spider genera Enoplognatha, Theridion, and Paidisca in America north of Mexico (Araneae, Theridiidae)
H.W. Levi. 1957. Bulletin of the American Museum of Natural History 112, article 1, 123 p.