Aggresive house spider

Agelenidae tegenaria-agrestis

Swift-running spider distinguished from non-poisonous funnel web spiders by chevron shape on its abdomen and legs which are not banded like other funnel web spiders.

The aggressive house spider, Tegenaria agrestis, is becoming one of the most common spiders in the Northwest. This spider was first reported in the Seattle area in 1930. It is a prevalent spider in basements and in window wells of houses. It rarely climbs vertical surfaces and is usually found only on the ground or lower floors. Experts have called it the aggressive house spider because it bites with little provocation when cornered or threatened. The aggressive house spider is important medically because of its ability to cause necrotic spider bites. (A necrotic bite causes tissue to die.) The aggressive house spider is a long-legged, swift running member of the funnel web spider family. The brown abdomen has a distinctive yellowish chevron pattern. The legs are a uniform brown without the darker brown bands that other nonpoisonous funnel web spiders have.