Cobweb Spiders

Also known as Theridiidae, the cobweb is the name given to the araneomorph spider family comprising of more than 3000 species divided into 124 genera.  The species belonging to this family is the commonest arthropods found worldwide in human dwellings.

Physical Description & Identification

Adults

Size: Most of them are between 3 mm and 10 mm in length, with females being larger than males.

Color: The color pattern differs from one species to the other, though most of them have a brownish-gray body with dark markings.

Other characteristics: They possess a comb of setae or jagged bristles on the fourth pair of their legs, which earn them the name comb-footed spiders. Their abdomens are round, oval or spherical, while the females of this family possess long, slender legs.

Eggs

The eggs are placed within the silken sac case and placed near the web of the female spider, with each sac having about 30 white eggs.

Spiderlings

The spiderlings stay with their mother for a while after maturation. Then, they disperse to be on their own.

The Web

They make messy, tangled webs, which remain in a good state for a long span, rarely replaced.

Are the Species of the Theridiidae Spider Family Poisonous and Do They Bite

Spiders of this family are said to be non-aggressive, not biting humans unless provoked or agitated. Moreover, their venom is also said to be low on toxicity which makes these species less dangerous to human beings.

Quick Facts

Other Names Tangle-web spiders, comb-footed spiders
Lifespan Approximately one year
Distribution Continents of America, Asia, Africa, and Australia
Habitat Dry, dark and dingy areas such as attics, garages, eaves, sheds, porches, and basements
Common Predators Not known
Diet Small insects and also on other spiders though occasionally

Did You Know

  • One of the species belonging to this family, Theridion grallator, is alternately called the happy-face spider since its pattern is similar to that of a grinning clown or smiley face.
  • The Theridion genus is said to be the largest having over 600 species.