The Hobo Spider is a Palaearctic species (a funnel web weaver) that has been introduced in the Nearctic in the Pacific Northwest, including southern BC. It is widespread across southern BC (mostly synanthropic (found close to human habitation), but also in natural habitats in southwest and south central BC), and Alliford Bay (Moresby Island). Populations are very localized (Salomon 2007). In coastal British Columbia, this species is most often found in relatively hot, dry habitats and naturally co-occurs with the giant house spider, Tegenaria duellica
(and, in some localities, with the western black widow, Latrodectus hesperus
). Both Tegenaria
species were introduced to the Pacific Northwest in the early 20th century, rapidly spread and have now become invasive (Vetter et al. 2003, Salomon 2007). In Canada, hobo spiders are found only in southern British Columbia.
Hobo spiders have been falsely accused of being responsible for medically significant lesions in humans. No verified case of hobo spider envenomation exists. A variety of medical conditions are often misdiagnosed as being the result of spider bites. For appropriate and effective treatment, it is important that strange lesions or other symptoms be accurately diagnosed. Read the article in Canadian Family Physician by Robb Bennett and Rick Vetter on the misdiagnosis of spider bites in Canada. For a review of the medical mythology associated with spider bites, read the article in Lancet by Geoffroy Isbister (2004). For excellent information regarding those "mystery bites and itches" that are commonly mistaken for spider bites, read this article.
Accurate identification of most spider species is difficult to achieve without the use of magnification – either a hand lens (for some larger species) or a dissecting microscope (most spiders). Examination of the genitalic characters of adult male or female spiders is the most reliable method for spider species identification. Hobo spiders are relatively large and can usually be identified accurately with a hand lens and comparison with diagnostic drawings such as those published by the Garry Oak Ecosystem Recovery Team (GOERT).
Author: Robb Bennett, Research Associate, Royal BC Museum.