Cobweb SpiderIdentification, facts & practical guidance

Cobweb spiders are Theridiidae, a diverse family of spiders that includes house spiders, false widows and true widows.

Compiled by the InsectLibrary Team · Updated 2026-09-30 · Editorial policy

Identification and lookalikes

Steatoda castanea - Steatoda castaneano rights reserved. https://creativecommons.org/publicdomain/zero/1.0/ Source: https://www.inaturalist.org/observations/403851129

Asagena americana - Two-spotted Cobweb Spiderno rights reserved, uploaded by Mirko Schoenitz

Dipoenoides funebris - Eastern Triangular Cobweaver(c) John P Friel, some rights reserved (CC BY), uploaded by John P Friel

A rounded abdomen and irregular three-dimensional web can suggest this group. These traits do not identify a widow; species-level markings and geographic context still matter.

Why the family name is not a safety label

Members of the family differ in their biology and medical significance. Information about Latrodectus should not be applied automatically to Steatoda or other cobweb spiders.

What to do next

Compare a clear photograph with the brown widow, black widow and house spider guides. Avoid handling an unidentified spider; for a suspected widow bite, seek medical advice.

Cobweb Spider: species profiles

Explore 154 species profiles covered by this guide, with recorded names and available photos.

Steatoda castanea

no rights reserved

Two-spotted Cobweb Spider

Asagena americana

Eastern Triangular Cobweaver

Dipoenoides funebris

Horned Parasitic Cobweaver

Neospintharus trigonum

Coleosoma floridanum

Rhomphaea projiciens

Steatoda erigoniformis

Fingered Cobweaver

Hentziectypus globosus

Theridion glaucescens

Theridion neomexicanum

Robertus vigerens

Silver Cobweb Weaver

Euryopis argentea

Showing 12 of 154 species. Browse all in Araneae →

Sources and further reading

ipm.ucanr.edu - widow spiders and their relativeshttps://ipm.ucanr.edu/home-and-landscape/widow-spiders-and-their-relatives/

References support the subject discussed here; they do not certify every imported directory record. Regional sources describe their own locations. Read our source and correction policy.