Hobo Spiders are common in the Pacific Northwest but have been known to live in Utah since the 1990s. The bite of the Hobo Spider is often misattributed to the Brown Recluse, which does not live in Utah. Both spiders can cause necrosis, or dying flesh, in the area of the bite.
Hobo Spiders build funnel-shaped webs in holes and crevices near the ground. They are not good climbers, but they are fast runners.
The Hobo is considered a dangerous spider, but severe bite cases have been difficult to document. Victims often do not see or catch the spider, and the necrotic lesions attributed to spider bites can be caused by other conditions. It's incredibly difficult for scientists to "milk" spiders for venom, which hampers scientific study of spider bites.
Utah State University offers the following information about Hobo Spider bites:
- The severity of envenomation depends partly on the amount of venom injected, as well as the sex and age of the spider. The bite of the hobo spider is relatively painless and is reported to feel like a pin prick.
- Within 15 minutes of the bite, numbing sensations may occur at the bite site or other areas of the body (such as the tongue), and dizziness may occur.
- After about 1 hour, reddening around the bite begins and enlarges in area. The bite site becomes hardened and swollen within about 18 hours. Blistering at the bite site, severe headache, visual or auditory disturbances, weakness, and joint pains may occur within the first 36 hours.
- Within 24 to 36 hours, a discharge of fluids and blistering may occur, and after 2 or 3 days the area around the wound may blacken. A cycle of sloughing and crusting at the ulcerated site may continue for some time, often requiring six months or more for complete healing to occur.