Our Common Pests

 Other Spiders

Other Common house spiders in our Area

In addition to Black Widow Spiders, Yellow Sac Spider, Recluse Spiders the species mentioned , there are only a few other species of spiders in our area that may on occasion bite humans. (Remember, if the bite of any spider causes an unusual or severe reaction, contact a physician.)

One kind of red and black jumping spider, Phidippus johnsoni, may bite if it is disturbed, but the bites are usually not serious. The female spiders are black with red on the top side of the abdomen whereas the males are all red. These spiders range in size from 1/4 to 1/2 inch long.

Tarantulas are long-lived spiders that occupy burrows in the ground during the day but often come out at night to hunt insects near the burrow. They commonly are feared because of their large size and hairy appearance. Some poisonous tarantulas occur in tropical parts of the world, but the bites of California tarantulas are not likely to be seriousat worst, they are similar to a bee sting.

The hobo spider, Tegenaria agrestis, also called the aggressive house spider, is a common spider in the Pacific Northwest. It builds funnel-shaped webs in dark, moist areas such as basements, window wells, wood piles, and around the perimeter of homes. It is a large (1 to 13/4 inch, including legs), fast-running brown spider with a herringbone or multiple chevron pattern on the top of the abdomen.

Bites most commonly occur when a person picks up firewood with a spider on it or when a spider finds its way into clothing or bedding. Reactions to bites of the hobo spider are similar to those caused by brown recluse spiders. The major difference between the two is that sometimes the bite of the hobo spider is accompanied by a severe headache that does not respond to aspirin. The hobo spider has not been documented in California, but it has been documented as expanding its range into other states that border Washington and Oregon.

One spider frequently found indoors is the common house spider, Achaearanea tepidariorum, which makes a cobweb in corners of rooms, in windows, and in similar places. Another is the marbled cellar spider, Holocnemus pluchei, which was introduced into the state in the 1970s and has since displaced the once common longbodied cellar spider, Pholcus phalangioides, a longlegged spider that resembles a daddy-longlegs. These spiders are incapable of biting humans because their fangs are too short to pierce people's skin; they primarily cause problems by producing messy cobwebs.

Various kinds of small hunting spiders may wander indoors and occasionally, rather large, hunting-type spiders are discovered in homes or garages. Often these are fully grown wolf spider or tarantula males that have reached maturity and are searching for females. When these spiders are wandering, one or more may accidentally get indoors. New houses and other structures in developments may be invaded by wolf spiders that have lost their usual outdoor living places. The more insects there are inside a building, the more likely it is to have spiders living there. Usually spiders are most abundant in fall following the first few rains of the season. Immature and adult female burrow-living spiders sometimes wander for a time during the rainy season if they have had to abandon wet burrows.