This species currently is believed to be native to Europe but was first discovered in North America in 1929, reaching Seattle in 1960.
This is a third species in this genus that is found in the Pacific Northwest, with a much more restricted range than T. agrestis or T. domestica. It can be found along the coastal areas from B.C. south into northern Oregon. It appears to out-compete the Hobo spider as homes in Seattle that previously were well stocked with Hobo spiders in the 1960’s were instead occupied primarily by T. gigantea by the 1980’s. It is commonly found both indoors and outdoors but is nocturnal, hiding during the daytime beneath materials on floors or on the ground and hunting at night.
Despite its common name this is not a particularly large spider, with females achieving a body length of no more than ¾ inch. Typical of this genus will be a “herring-bone” pattern of dark stripes on the top of the abdomen. There are also 2 dark stripes running down the top of the thorax, but these various darker markings may also occur on other unrelated spiders. The spiders are brown, have long legs, and tend to lay fairly flattened. They have 8 eyes, with 6 of the eyes enlarged and facing forward to maximize their vision for spotting prey. Confirmation of the specific identification must be done by an expert.
Characteristicts Important to Control:
Indoors the spiders and their webs may be removed with a vacuum cleaner. When the webs are found on plants outdoors the ideal response is to leave them alone and to enjoy them. They are feeding on other unwanted insects and are highly beneficial. If necessary due to customer pressure the plants may be treated with a labeled insecticide for short term relief from the spiders and the web removed with a stream of water.