Hobo spider?

Asked August 13, 2015, 12:37 AM EDT

Pretty sure we just killed a hobo spider in our home. This is the first one we have seen in the home since we moved here 6 years ago. Should I be expecting more or do you think he hitched a ride in on something?

Clark County Washington

1 Response

Nope, not a Hobo Spider. This is a Giant House Spider. It’s that time of year again when we begin to see these sometimes huge spiders in our home. The frantic males are running around looking for mates in the late summer and fall. As scary looking as they are, they are beneficial, eating the other bugs that annoy us or bother our plants.

Concerned that it’s a Hobo Spider (Tegenaria agrestis)? See the stripes on the cephalothorax (the part of the body to which the 8 legs are attached)?

  • If you see stripes, it’s NOT the Hobo Spider.
  • If you see striped legs, it’s NOT the Hobo Spider.
  • If you see a dark orange body and legs, it’s NOT the Hobo Spider.
There are other distinctions, but these are the most easily observed differences. Don’t want these visitors? Button up your house--seal all points of entry--around windows, plumbing, gas, and electrical entrances to your home, and make sure the door sweeps or seals are intact. To learn more, see Pestsense Fact Sheet: http://pestsense.cahnrs.wsu.edu/Search/MainMenuWithFactSheet.aspx?CategoryId=17&ProblemId=842

And about the Hobo Spider--it’s gotten a bad rap--it’s not the dangerously venomous spider as everyone previously thought. From Jenny Glass, Plant Diagnostician at the WSU Puyallup Plant & Insect Diagnostic Laboratory:

Bites could happen when a hobo spider is trapped against the skin, but well-documented hobo bites are scarce so not much is known about them. It is unclear if hobo spiders can cause necrotic bite wounds – much of the evidence is circumstantial or is repeated as citations in medical literature. Research has shown that hobo spider venom is not capable of causing severe cellular damage such as a necrotic wound. Hobo spiders originally came from Europe and they haven’t been reported to be harmful there. http://www.doh.wa.gov/CommunityandEnvironment/Pests/Spiders

For more information on Spiders found in Washington, see WSU Publication EB1548E