Spiders are not insects
but belong to the arachnids, I have included them here because most people think
of them as insects.
that nearly half the total number of spider species known to occur in Canada are
found in and quite often only in B.C., and given the
importance of spiders to all ecosystems in which they live , one must
wonder why these beautiful creatures have received such little attention in
the province and on Vancouver Island.
Spiders are ferocious creatures living in the
arthropod world. Theirs
is a matriarch society ruled by the females where males can be just a meal.
The study of these creatures on
Vancouver Island has for the most part, been conducted by a few
amateur but dedicated collectors.
in British Columbia and you’ll be less than a meter from a spider. With more
than 700 known species in the
province, arachnids are everywhere, from mountaintops to intertidal zones. These
creatures are always exciting to watch, from the jumping spiders that
dance to impress possible mates, to the yellow crab spiders that disguise
themselves as flowers.
have an ominous, but often undeserved reputation. Though most spiders are
venomous and considered predators, of the thousands of species found in Canada,
few are actually considered a health threat. In fact, spiders are actually
helpful in controlling other pests in the home or garden since they feed on
other insects and spiders. They generally bite and inject venom into their
spiders are often unpopular, the venom of most species is not very toxic to
humans, usually resulting in no more than a slight swelling, inflammation, or
itching sensation. Most spiders’ fangs are too small or weak to puncture human
skin. Spiders usually will not attempt to bite unless accidentally trapped
against the skin or grasped, although some species actively guard their egg sacs
or young. Spiders,
however, rarely bite humans.
One of the
most common misconceptions about spiders is that they are insects. Spiders are
arachnids and are actually more closely related to mites, ticks and scorpions.
Spiders have two body parts and eight legs and usually six to eight eyes, while
insects are classified by having three body parts, six legs and generally two
compound eyes or up to three single eyes.
life span of a spider is usually one to two years, but some can live up to 20 years.
eggs within a silken egg sac that is often ball shaped and either hidden in a
web, affixed to a surface, or carried by the female. Spiders may produce several
egg sacs, each containing up to several hundred eggs.
grows by shedding its skin about four to twelve times before maturity. In many
species, the mature male often wanders about in search of a mate while the
female has a territory.
spiders produce silk, which is secreted as a liquid through the spinnerets and
hardens on air contact. Spiders use silk for a variety of purposes, such as
making egg sacs, capturing prey, holding prey, making shelters or retreats, and
transferring sperm during mating. Also, spiderlings extrude silk threads that
enable them to be transported by the wind, a process called ballooning.
predators that typically feed on living prey. They produce venom that is
poisonous to their normal prey of insects, mites, and other small arthropods.
Venom is injected through the hollow fangs to immobilize the prey and begin the
only ingest liquids, so they either inject or regurgitate digestive fluids into
the prey. They then suck in the digested liquid food.
Spiders use a
variety of tactics to capture prey. Some species are web builders that use
webbing to ensnare their prey. Others are hunters that actively search for
their prey. Passive hunters are spiders that lay in wait for their prey rather
than searching for it.