Other Common Names
Greater European House Spider
Synonyms and other taxonomic changes
Previously genus Tegenaria
(transferred to Eratigena
in August 2013). (1)
Tegenaria duellica (= T. gigantea) & T. saeva were all synonymized with T. atrica (now Eratigena atrica) in that same paper.
All measurements are for only the body, and do not include the legs.
Females: approximately 16-18 mm.
Males: smaller, approximately 10-12 mm.
No banding on the legs, but proportionally longer legs than its relatives Eratigena agrestis and Tegenaria domestica.
Main population located in BC, OR, & WA.(2)
Also collected from isolated populations in AB, SK, QC, NS, NF.(3)
Please note that in 2013, three species were synonymized (duellica
, & atrica
), so many of the populations in eastern Canada were of what was (then) considered a separate species.
In comparing the ranges of E. atrica and E. agrestis, E. atrica is more common in coastal locations and E. agrestis dominating the interior. Anecdotal evidence suggests that, where the two species are sympatric, E. atrica “out-competes” E. agrestis although the nature of their relationship is unclear. (Link #2, See Internet Reference section below.)
In an unpublished study (1980s) by Rod Crawford
, Curator of Arachnids at the Burke Museum, E. atrica
was found to outnumber E. agrestis
by about 50 to 1 in Seattle-area house properties that had been occupied largely by E. agrestis
20 years before.
"Natural" populations found on cliff faces and rocky areas. ~ Rod Crawford
When found around human structures, it is often located in darker areas, such as flower beds, wood piles, and areas where it can weave a funnel-web. When it is found in homes, it often is found in the darker recesses of the basement, such as corners. It is a nocturnal spider, so generally it is discovered when the lights are turned on and the spider darts for cover (and/or its web).
Insects, possibly other spiders.
Life cycle images:
(spiderling, juvenile, molted skin, adult female & male)
This spider (like its relatives T. domestica
and E. agrestis
) was imported from Europe into the ports of the Pacific Northwest. The first known N. American record was from Vancouver Island in 1929. It did not reach Seattle until 1960.
The greater European house spider (E. atrica) is not dangerous to people. Some people may be intimidated by their size as male legspans can reach 4 inches (100 mm). However, Rod Crawford has never known one to bite a human (though they certainly could if they tried); they are so docile he uses them as hands-on demonstrators for school children.
The Hobo Spider (E. agrestis
) is often confused with this spider. If you are unsure of the exact species, just be mindful of this confusion, and use caution when dealing with the spider. (See E. agrestis
for more information about the hobo spider).
The presence of giant house spiders is a deterrent to the establishment of hobo spiders indoors. It out-competes and displaces the hobo spider indoors and male giant house spiders often kill male hobo spiders (without necessarily eating them)!
: A good fact sheet about the Giant House Spider (Greater European House Spider)
2) Newsletter of the Entomological Society of British Columbia
, Volume 22, Number 1 July 2002 (an article by Robb Bennett: Hyperbole and Hysteria on the Path to Enlightenment – a Review of Current Tegenaria Projects of Relevance to Canadian Arachnologists