Parasteatoda tepidariorum

The Common house spider, sometimes called the American House Spider, is an extremely common spider in North America and South America, as its name suggests. They build their tangled web in secluded locations, which can also house eggs contained in one or more spherical sacs. Their behavior on webs is quiet and efficient.

Description

They are generally dull in appearance, with patterns consisting of brown shades for coloration, often giving a vague spotted appearance that is particularly noticeable on the legs. Their average body size is a quarter-inch long, but they can be an inch (2.5 cm) or more across with legs outspread. These traits combined allow the spiders to blend into the background and escape notice.

Like some other species of the family Theridiidae, P. tepidariorum shares a body shape and size that makes it similar to widow spiders, which have venom that is classified as potentially dangerous.

Interaction with humans

These spiders are not aggressive. They are not known to bite people frequently, nor is their venom known to be dangerous to human beings. When removed from their webs their poor vision and body type renders them helpless. Their only concern seems to be to find and return to their own web or build another one. They do not wander around inside houses except to find a secure place to build a web. Since these spiders are harmless and their diet consists of pests such as flies and mosquito as well as other small invertebrates found in houses. Tolerating their presence in human homes is beneficial.

Similar named species

In Europe Tegenaria domestica and similar species are usually known as the Common House Spider, which are in family Agelenidae. They often make large sheet like webs where the walls and ceiling meet,and live in a small funnel. Like almost all spiders, these are also harmless.

Actually there is a wide range of very diverse spiders that bear the name "house spider" or similar around the world, obviously the only thing between them being that they occur frequently in houses. It is therefore especially in this case often more helpful to refer to them by their scientific names.

Footnotes

References

• (2000): Achaearanea tepidariorum at Animal Diversity Web
• (2008): The world spider catalog, version 9.0. American Museum of Natural History.

External links

• Pictures of A. tepidariorum (Free for noncommercial use)
• common house spider on the UF / IFAS Featured Creatures Web site

Image Gallery