Achaearanea tepidariorum
house spider

These spiders can currently be found all over the world, although they are thought to be native to the neotropics (Milne and Milne 1980)

The house spider builds large webs in the corners of rooms, under furniture, in angles between fences, and often between stones. They usualy take advantage of the space that is going to provide them with the most abundant amount of prey. They can be found during any season. (Emerton 1902)

The color varies 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 is high in the front and narrow toward the spinnerets. In dark specimens the abdomen has six transverse black marks that curve upward and are thicker in the middle. The marks are connected by black spots at the ends and they are bordered by a silvery white line. The upper white mark often forms a white spot in the center of the abdomen. These marking are smaller and less defined in lighter species.

The females usually range from 5 to 6 mm long. Their first pair of legs are almost three times the length of the whole body. The legs are yellow with dusty annuli at the ends of each segment.

The males are smaller than the females and range from 3.8 to 4.7 mm in length. However, they have longer legs which are orange-brown and darker at the joints. (Emerton 1902; Kaston 1972) (Emerton, 1902; Kaston, 1972)

The house spider has a few behavorial characteristics that are not common of all spiders. Many of these have to do with the structure of the web. One part of the spider's web is woven more closely than the rest of the web. This part is also covered with an extra layer of silk, adding stability. The house spider stands in this part of the web but does not construct a tent-like structure as many spiders do. When the web is constructed in open spaces the spider will often carry a small piece of leaf into the web under which it hides.

The house spider builds its web in the dark, taking advantage of every angle where insects might be caught. The webs of young spiders are much more regular than those of the adults. These irregular tangle webs are made of sticky strands that catch dust and prey. These webs are commonly found in houses and are usually referred to as cobwebs. (Foelix 1982; Milne and Milne 1980) (Foelix, 1982; Milne and Milne, 1980)

Achaearanea tepidariorum eats insects, as do all spiders. It catches its prey by waiting in the web until a large insect, such as a Camel Cricket, gets caught in the sticky web. When this happens the spider proceeds to throw more silk onto its victim and then pulls it up into the web. Observation has shown that these spiders tend to change the sites of their webs if they are not catching enough prey. (Foelix 1982; Milne and Milne 1980)

The household spider has no major negative effect on humans, it is simply an annoyance in that its webs tend to collect dust and are unclean.

The spider is beneficial to humans by catching and eating unwanted insects that are present in the house.

This species is extremely common and requires no special protection.

This species was originally assigned to the genus Theridion. (Milne and Milne 1980)