Much good information on hobo spiders is already on the Internet. So we thought we would provide links to some good hobo spider web pages and include excerpts from their pages as a way to summarize some useful info about these spiders.
Hobo spider links
Spiders, by Washington State University Extension, has a lot of great information regarding hobo spiders and other spiders. You might want to start here.
The Hobo Spider web site (hobospider.org) Everything you ever wanted to know plus photographs. From this site: "The hobo spider, Tegenaria agrestis, is a moderately large spider of the family Agelenidae which is indigenous to western Europe that was introduced into the northwestern United States (Port of Seattle) sometime before the 1930s." And: "Urban populations of hobo spider do appear to be decreasing in some areas, such as Seattle, Washington, where the giant house spider, Tegenaria gigantea, has become abundant."
BugGuide.net's page on Hobo Spiders. From this page: "A common misconception is that agrestis means "aggressive", giving it the name "aggressive" house spider. This spider is not aggressive, and would rather flee than fight, unless it feels threatened without the option to escape." And..."Very difficult to ID from photos. The actual spider (not a photo) needs to be examined by an expert for a definite identification."
How to Identify (or Misidentify) the Hobo Spider (an external PDF file), by R. Vetter and A. Antonelli. "The hobo spider is found throughout Washington and makes a funnel web which is a trampoline-like flat sheet leading back into a hole between bricks, under wood or in shrubs. However, there are many closely related species of spiders which also make similar webs so just because you see funnel webs on your property, does not mean that there are hobo spiders in those webs. " And: "Most people want a world with simple black/white answers but you must realize that there many shades of gray in between and this is the reality of spider identification."
Hobo or Not a Hobo–Th at IS the Question... A Photographic Key to Discerning Hobo From Non-Hobo Spiders, from Utah State University Extension, provides a dichotomous key for spiders that is intended for use with a microscope. The main purpose of the key is to identify the hobo spider as compared to other Tegenaria species and members of the wolf spider family (Lycosidae).
Hobo Spider Update from Whatcom County/Washington State University Extension. From this PDF: "In our area, we have a complex of three species of house spiders. Unfortunately, all three species look very similar. The three species include the domestic house spider, Tegenaria domestica, the giant house spider, T. gigantea, and the Hobo spider, T. agrestis. Visual characters that we previously used to ID house spiders are inconsistent and have lead me to misidentifications when these are all I use." And: "Even though I am confident that the occurrences of hobo spiders are on the decrease in households, spiders should be handled with caution regardless of the species. Even after identification, it is still good to suggest caution to the customer next time they encounter a spider. Bites are relatively rare considering the number of hobo spiders in our area. Severe bites resulting in necrosis usually occur when the spider is trapped up against your skin. If you roll over onto one in your bed, that poor spider has all night to bite you (hobo bites reportedly produce little or no pain)." Finally, and perhaps most importantly: "Of all spider specimens brought in, less than 2% have been hobo spiders. Almost all house spiders collected are gigantic house spiders (the good guys). ...The giant spider is a fierce competitor (and sometimes a predator) of the hobo spider and will keep hobo spiders out of its territory. In addition, the giant spider is relatively harmless and bites are rare."
For questions about information on this page, please contact Kate O'Laughlin, Ecologist.