 Hobo
Spiders (Tegenaria agrestis) -
These spiders belong to the Tegenaria family of spiders. The adult Hobo
spider is a moderately large (12-18 mm body length) brown spider, with long,
unmarked legs (legs included, a typical specimen would fit nicely on
a silver dollar). The dorsal abdomen exhibits a "herringbone" or multiple
chevron pattern, which may be quite obscure in darker individuals. The male
sports two pedipalps (antennae like protuberances) between the two
front legs, which are swollen at the ends, looking somewhat like a pair of
boxing gloves; these "boxing gloves" are actually the male genitalia, not
"fangs" or "poison sacs". The female generally has a larger abdomen than the
male, and does not have swollen "boxing gloves" at the ends of the pedipalps.
Several other spiders resemble hobo spiders; only an arachnologist, or other
specifically trained person should attempt to make a positive identification
of this species: In an instance where a spider has bitten a person, it is
imperative to obtain positive identication only from
a qualified professional arachnologist.
 Hobo
spiders belong to the family Agelenidae or
funnel web weavers which is indigenous to western Europe
that was introduced into the north western United States (Port of Seattle)
sometime before the 1930's. The means of the spiders' introduction into the
United States was almost certainly commercial shipping vessels carrying
cargo originating from agricultural areas of Europe. It is highly probable
that they were transported to and arrived in the Port of Seattle as egg
cases attached to wood, etc., rather than as live spiders. Considering the
seasonal nature of the Hobo Spider, it is highly unlikely that a viable
breeding population would have developed in the United States based upon the
occasional introduction of adult or juvenile specimens.
In its native Europe the Hobo Spider is a resident of fields, rarely
entering human habitations due to the presence of major competitors,
particularly the giant house spider, Tegenaria gigantea, which is a
common resident of houses and other man-made structures in Europe;
therefore, human contacts with the hobo spider are uncommon in Europe. In
the United States however, the Hobo Spider rapidly adapted to living in
urban areas, and without the widespread presence of a dominant competitor,
became abundant and began to extend its range; by 1968 it had become
established as far east as Spokane, Washington and Moscow, Idaho, and as far
south as Corvallis, Oregon.
In the late 1960's and early 1970's physicians in Idaho, Oregon and
Washington were presented with cases of probable spider bite that closely
resembled bites caused by the brown recluse spider, Loxosceles reclusa.
Studies conducted between 1974 and 1982 suggested that another spider was
probably the actual agent of these bites. Finally, in 1983, field studies
revealed that the Hobo Spider was the actual cause of such bites in the
northwest, and the spiders' ability to produce necrotic lesions and systemic
illness was demonstrated in the laboratory in 1986.
The reason hobo spiders have a reputation for being so aggressive
is because they have very poor eye sight and have to aggressively attack
their prey to catch it. Their web is not sticky either which makes it harder
for them to catch prey. Therefore with their poor eye sight, they think
humans or anything that moves probably, are prey and attack. In around 50%
of bites, no venom is injected so their reputation is probable overated too.
However when it is injected, necrosis occurs and the resulting wound
can take years to heal with much skin being eaten away!
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Giant House Spider (Tegenaria Gigantia) -
The Giant house spider (Tegenaria
duellica; formerly known 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.
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| Females can reach 18 mm in length, 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; Earthy tones of brown and muddy red or
yellow. They also have conspicuously hairy legs and abdomen
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Information
and pictures were taken from children's projects and where credited to that
child does not claim to be original information. Where possible, permission
to reproduce has been sought. Any infringement of copyright is purely
unintentional.
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