Giant house spider
|Giant house spider|
The Giant house spider (Tegenaria duellica; sometimes also referred to as T. gigantea) is a member of the genus Tegenaria and is a close relative of both the Domestic house spider and the infamous Hobo spider. The bite of this species does not pose a threat to humans or pets.
Female body size can reach 18 mm in length (making it the largest members of the family), with males having a slightly smaller body at around 12 mm to 15 mm in length. The female leg span is typically around 45 mm. The leg span of the male is highly variable, with spans between 25 mm to 75 mm being common.
The Giant house spider has the same coloration as the Domestic house spider; it has earthy tones of brown and muddy red or yellow. They also have conspicuously hairy legs and abdomen.
The Giant house spider is indigenous to north western Europe. However, it was unwittingly introduced to the Pacific Northwest of North America circa 1900 due to human activity and strongly increased in numbers for the last decade.
The webs built by the Giant house spider are flat and messy with a funnel at one end. The spider lurks in the funnel until a small invertebrate happens to get trapped in the web, at which point the spider runs out and attacks it.
They usually build their webs in corners (on both the floor and ceiling), between boxes in basements, behind cupboards, in attics, or any other area that is rarely disturbed by large animals, or humans. Often found near window openings.
Males can often be seen wandering around houses during the late summer and early autumn looking for a mate.
Like most spiders, the spider possesses quite a potent venom to subdue its prey. Since T. duellica can penetrate regular human skin on normal occasions, the effects of agatoxin are more likely to be felt by the victim. No medically significant reports of its bites exist up to the present date.
With speeds clocked at 1.73 ft/s (0.53 m/s), the giant house spider held the Guinness Book of World Records for top spider speed until 1987 when it was displaced by sun spiders (solfugids) although the latter are not true spiders as they belong to a different order.
Relationship with Tegenaria agrestis 
A population of Giant house spiders is popularly thought to be a deterrent to the establishment of Tegenaria agrestis, known in North America as the hobo spider, and considered by some to be more likely to bite humans. Giant house spiders may compete with hobo spiders for the same resources. Hobo spiders grow no more than a body size of 15 millimetres (0.59 in) long as where the larger female giant house spider can have a body size of 18 millimetres (0.71 in), but has proportionately much longer legs.
This species was referred to as Tegenaria gigantea until 1995, when it was first suggested that this name was a synonym of T. duellica (published in 1875), making the latter the oldest available name. Other authors suggested that T. gigantea was a synonym of T.saeva, but molecular evidence shows that these are distinct taxa, not synonyms.
Many arachnologists still prefer the name Tegenaria gigantea since there is no conclusive evidence that the T. gigantea found in the Pacific Northwest are indeed the same species as the T. duellica described by Simon in 1875. Simon's descriptions are vague, and the type specimens of duellica have been lost, preventing any direct comparison that would establish synonymy. Additionally, T. gigantea is not known to have spread outside of England before the 20th century, whereas Simon's type specimens for T. duellica are from Spain, which suggests that they are distinct species.
In popular culture 
Humorist David Sedaris has written about his relationship with Tegenaria duellica. His essay "April in Paris" documents his growing affection towards and domestic association with Giant House spiders, particularly one named April. The essay can be found in the collection When You Are Engulfed in Flames.
- Tegenaria duellica fact sheet
-  Bugguide, Tegenaria agrestris
-  Bugguide, Tegenaria duellica
- P. J. P. Croucher, G. S. Oxford, J. B. Searle (2004) Mitochondrial differentiation, introgression and phylogeny of species in the Tegenaria atrica group (Araneae: Agelenidae). Biological Journal of the Linnean Society 81: 79–89. doi:10.1111/j.1095-8312.2004.00280.x