Habits
Most spiders, being nocturnal are seldom seen during the day
unless disturbed. Those which depend on webbing to snare their prey seldom move
far and hide in a crevice, curled leaf or appear camouflaged as twigs. Hunting
spiders, many of which are ground dwellers are less dependent on webs and move
around in the dark hours in search of food. Males seek out the females at
mating time. Male spiders have long palps alongside their jaws. These sometimes
could be confused as another set of legs, but they are long for the purpose of
picking up their sperm and depositing it in the genitalia of the female. After
mating, the male often becomes an immediate high protein meal to assist the egg
production of the female. The eggs are usually deposited into a silken sac
produced by the female. The spiderlings hatch inside the sac and moult once
before they emerge. They must find their own food and disperse quickly in
search of it. By successive moults they become adult and those that survive can
usually be expected to live for 1-3 years.
Whether the spider traps prey in a web or hunts to
capture it, the victim is injected with venom through the fangs. This
immobilizes it. The body is then squeezed and the erupting liquid is sucked in
through the small mouth behind the fangs at the base of the palps. Most species
can survive for months without food. This is just as well, as insect prey is
usually scarce in the colder months. Silk or web is produced from glands in the
abdomen and deposited through the spinnerets. The orb-weaving spiders produce
an adhesive silk for the snare area of the web and drier silk for the radii and
guy lines. In some species, spiderlings let out sufficient web into the air to
lift and carry them away.
Biology
Spiders can be readily distinguished from insects; they have 8
legs instead of 6 and they have 2 body segments instead of 3 - the head and
thorax are fused into one unit which contains eyes, mouthparts and legs. The
abdomen section is soft and also houses the reproductive organs, the silk
glands and spinnerets and the respiratory openings which are visible on the
undersurface like the pages of a book. This large surface area achieves the
transference of oxygen into the blood. There are usually 4 pairs of eyes; each
a simple lens. The arrangement of these eyes in a pattern is constant for each
species and is an aid to identification. The fine hairs and setae on various
parts of the body are said to be sensitive to taste, touch and vibration.
Management
As with all pest management programs, an integrated pest
management approach is an integral part of successful spider control. All
control procedures are preceded by a thorough inspection of the entire premises
to define the extent of the problem. Precise application is favoured over
'blanket' spraying and sometimes even changing the position or the colour of
nearby lights can reduce the number of insects attracted to them and hence the
spider population.