Achaearanea tepidariorum, the spider responsible for most cobwebs

Description

House spiders range in color from a dirty white to almost black. The cephalothorax is yellow brown and the legs are light yellow with brown or gray rings at the ends and middle of the joints. The abdomen has six transverse black marks that curve upward; the marks are smaller and less defined in lighter-colored specimens.

Females range from 5 to 6 mm in length. Their first pair of legs are almost three times the length of the whole body. The legs are yellow. Males range from 3.8 to 4.7 mm in length. Their legs are noticeably longer in proportion to their body than those of the female, and are orange-brown in color.

Distribution and Habitat

The common house spider is found all over the world, although they are believed to be native to the neotropics.

This spider builds its large web in the corners of rooms, under furniture, in angles between fences, and between stones. It usually takes advantage of any space that provides the best "access" to the most prey.

Reproduction

The male and female may live together on the same web. The female lays her eggs in a brownish, pear-shaped egg sac that is 6 to 9 mm in diameter. Several batches of eggs may be laid in one season, and they simply hang in the web until hatching.

Habits and Behaviors

One part of the house spider's web is woven more closely than the rest of the web. This part is covered with an extra layer of silk, and it is in this part of the web that the spider stands in wait for its prey. When the web is constructed in an open space the spider may carry a small piece of leaf or other similar material into the web under which it hides.

The webs of young house spiders are much more regular than those of the adults.

The house spider's webs are made of sticky strands that catch dust and other debris as easily as prey. These webs are commonly found in houses and are what most people refer to as cobwebs.

Diet

A house spider catches its prey by waiting in the web until a large insect gets caught in the sticky threads. The spider then throws more silk onto its victim and pulls it up into the web. These spiders will change the sites of their webs if they are not catching enough prey.

Scientific Classification

phylum Arthropoda
class Arachnida
order Araneae
suborder Neocribellatae
family Theridiidae (cobweb spiders)
genus & species Achaearanea tepidariorum

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This page was last updated on August 01, 2017.