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 SPIDERS
Types: Hobo, Brown Reclusive, Black Widow
Organism,
mostly terrestrial, of the class Arachnida with four pairs of legs and a
two-part body consisting of a cephalothorax, or prosoma, and an unsegmented
abdomen, or opisthosoma. The cephalothorax is covered by a shield, or
carapace, and bears eight simple eyes. On the underside of the head (the
cephalic part of the cephalothorax) are two pairs of appendages, the anterior
pair called chelicerae and the second pair pedipalps, with which the spider
captures and paralyzes its prey, injecting into it venom produced in the
poison glands. The spider then liquefies the tissues of the prey with a
digestive fluid and sucks this broth into its stomach where it may be stored
in a digestive gland. Breathing is by means of tracheae (air tubes) or book
lungs , or both. Arachnid book lungs are similar to the gill books of
horseshoe crabs but are internal and adapted to a terrestrial habitat. Three
pairs of spinnerets toward the tip of the abdomen produce protein-containing
fluids that harden as they are drawn out to form silk threads. Several kinds
of silk glands and spinnerets produce different kinds of silk used variously
for constructing cocoons or egg sacs, spinning webs, and binding prey; other
light strands are spun out for ballooning, or floating, the spiders,
especially young ones, long distances on air currents. Spider silk is used for
the cross hairs in certain optical instruments. Spiders live chiefly on
insects and other arthropods; some large spiders ensnare and kill small
snakes, birds, and mammals. Many are cannibalistic; the female may eat the
male when courtship and mating are completed. Young, growing spiders can
regenerate missing legs and parts of legs. Several species of spiders have
bites that are exceptionally painful, or even dangerous to humans. Species of
black widow spiders, which are found in the warmer parts of the world
including the United States and S Canada, have a virulent neurotoxic venom.
The bite venom of the brown recluse spider of SE and S central United States
decomposes tissue, resulting in slow healing and sometimes leaving a sunken
scar as large as a quarter. Among the more interesting spiders are the
tarantula ; its relative the trap-door spider , which ambushes its prey from a
silk-lined burrow covered by a hinged lid; the orb weavers, which spin
beautiful circular webs; and the crab spider, jumping spider, and wolf spider,
named for their habits. Spiders are classified in the phylum Arthropoda ,
class Arachnida, order Araneae.
Hobo Spiders
Vary from ½" to 1 ¾" in body
length, with dark brown carapace. The abdomen has a chevron pattern that often
fades in older specimens. The hobo
spider actually helps control many insect pests. During late summer the male
travels about looking for mates. Hobo spiders bite when startled or
threatened. What starts as a small spider bite can grow into a large wound as
its powerful venom slowly kills the flesh. Hobo
spiders spin a distinct, dense, funnel-shaped web, typically along
foundations, in woodpiles, stacked equipment, or yard waste. The hobo spider
rarely climbs high on vertical surfaces, so search low to the ground. Hobo
spiders do not create all funnel-shaped webs, but treat them all carefully.
Wear gloves when working in the yard, cleaning your basement, or reaching into
dark areas.
253-226-2206
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