By the 1960's it had become well established in many parts of Washington, Oregon, and Idaho. Only recently, however, largely through the efforts of WSU entomologists, has T. agrestis been appreciated as a danger to human health. Hobo spiders have a two-year life cycle. Sexually mature spiders are abundant from mid-summer through fall. Males are more likely to wander in search of females during this period, especially in fall months.
Males are somewhat more venomous than females.
Bites commonly occur when a person picks up firewood with a spider on it or when a spider finds its way into clothing or bedding. The effects of hobo spider bites are similar to those of the brown recluse spider. The actual bite is not always painful, but a small, hard area typically appears within 30 minutes, surrounded by an expanding red welt that may reach 5-15 cm in diameter. Blisters form within 15-35 hours, which eventually crust over the cratered wound. A scab can develop over necrotic tissue that eventually sloughs off.