Spider Pest Control Information
Brown Recluse Spider
Araneae: Loxascelidae, Loxosceles reclusa(BROWN RECLUSE
SPIDER)
Brown
recluse spiders belong to a group of spiders commonly known as
violin spiders or fiddlebacks. This is because of a characteristic
fiddle-shaped pattern they have on their head region. The spider
is golden brown with the fiddle being dark brown or black. This
spider is not hairy and the fiddle pattern is often shiny. They
are about 1/4 to 3/4 inch long. Members of this small family are
known for their poisonous venom. They have six eyes in three pairs.
The cephalothorax is rather flat above and has a conspicuous,
lengthwise furrow in the midline at the rear third. Each foot
has two claws. Many of the wolf spiders are similar in appearance
and have similar markings as the brown recluse. They are large,
robust, hairy, and therefore they can be distinguished from the
brown recluse.
Brown Recluse spiders spin small, irregular webs under bark,
stones or other secluded areas. Their venom is especially poisonous
to people; those bitten often become ill and find that the wound
does not heal quickly. Both male and female brown recluse spiders,
as well as their spiderlings, are capable of injecting venom which
may result in serious lesion formation or systemic reactions.
The severity of the bite may vary. The symptoms may vary from
no harm at all to a reaction that is quite severe. Usually, the
brown recluse spider bite is not felt and the pain sets in from
six to eight hours later. A typical bite area may resemble a pimple,
postule or blister formation within six to 12 hours later. Mild
to severe pain accompanied by swelling may occur during this interval.
The surrounding tissue begins to darken, is irregular in shape
with sharply raised edges resulting in a sunken area which may
be several centimeters in diameter. Often there is a systemic
reaction within 24-36 hours characterized by restlessness, fever,
chills, nausea, weakness, and joint pain. Where the bite occurs
there is often tissue death and skin is sloughed off. In some
severe cases, a wound may develop that lasts several months. In
all cases, a physician should be notified. If at all possible,
kill and take the spider to the physician for positive identification.
Individual spiders can be crushed underfoot or sprayed with an
aerosol spray.
Brown recluse spiders are found primarily in the Midwest. Many
cases of bites are reported from Alabama, Florida, Georgia, Texas,
Kansas, Missouri, and Oklahoma. They are suspected of being in
other states as well. The edge of its range just reaches the tip
of western Virginia, but it occurs rarely in this state. The spider
commonly lives in basements, attics and garages of houses and
often hides behind boards and boxes. Bites often occur when the
spiders hide in towels or old clothes left in those areas. The
Brown Recluse has adapted quite well to indoor habitats. They
are commonly found in the storage areas of residences, including
areas such as attics, closets, bedrooms and other dark recesses.
This spider frequently inhabits clothing, toys, books, boxes,
furniture as well as transport trucks, tool sheds, tree houses
and little used or abandoned dog houses.
The brown recluse spider is nocturnal and prefers food such as
firebrats, crickets, cockroaches and other soft bodied creatures.
Earning their name well, the brown recluse spider ceases its wanderings
at first light. People are most commonly bitten in bed, while
changing clothes, or cleaning storage areas. Not only will this
spider hide in cracks and crevices of the home, they will often
climb into clothing or shoes that someone has laid out to wear
the following day.
A female deposits eggs in off-white silken cases about 1/3 inch
in diameter in sheltered, dark areas. Spiderlings emerge in 24-36
days and abandon the egg case. Development is slow, influenced
by weather conditions and food availability. They reach maturity
in 10 to 12 months and can survive long periods of time without
food or water. Immature spiderlings resemble adult brown recluse
spiders but have lighter coloration. Adult males and females will
vary from light tan to dark brown.
Black Widow Spider
Araneae: Theridiidae, Latrodectus mactans (BLACK WIDOW
SPIDER)
The
male black widow's abdomen is more elongate than that of the female,
with white and red markings on its sides. The female's abdomen
is almost spherical, usually with a red hourglass mark below or
with 2 transverse red marks separated by black. The legs of the
male are much longer in proportion to his body than that of the
female. The female is the most easily recognized, her shiny black
body giving great contrast to the red hourglass marking on her
round abdomen.
The black widow's range is from Massachusetts to Florida and
west to California, Texas, Oklahoma and Kansas. Although they
can be found in almost every state (and some portions of Canada),
this spider is most common in the Southern locales of the United
States. Black widow spiders are common around wood piles, and
are frequently encountered when homeowners carry firewood into
the house. Also found under eaves, in boxes, underneath unused
construction materials, inside wooden toy boxes, firewood boxes,
outdoor toilets, meter boxes, and other unbothered places.
The female black widow spider rarely leaves her web. The web
she constructs is an irregular, tangled, criss-cross web of rather
coarse silk. The core of the web is almost funnel shaped, woven
into a silken tunnel in which the female spider spends the majority
of her daylight hours. This web is altered and rebuilt in a regular
basis and is capable of capturing rather large insects. The female
wraps any captured prey with her silk, repeatedly turning her
victim with her legs as she applies more silk. After her victim
is covered in silk, the spider kills her prey by injecting her
venom. The prey might be eaten immediately or reserved for a later
feeding. After the prey is fed upon and the body fluids are sucked
from the victim, the carcass is cut loose and allowed to drop
to the ground. The female black widow is most often found hanging
upside down in her web, where she spends most of her daytime hours.
She stays close to her egg mass, defensively biting anything that
disturbs her or her egg sac. After laying her eggs, the female
black widow is hungry and more likely to bite a human. The female
black widow stores sperm, producing more egg sacs without mating.
Some females live more than three years.
Egg sacs are pear shaped (or oval), brown, papery and about ½
inch long. They hold from 25 to 900 or more eggs, which have an
incubation period of 20 days. The spiderlings disperse shortly
after emerging, tearing an opening in the egg sac and stay near
the sac. After several hours, these second instar spiderlings
balloon to the ground and scatter. Growth requires two to three
months, with older females dying in autumn after egg laying.
Of all spiders, the Black Widow is the most feared. The female's
venom is especially poisonous to people. Despite its reputation,
this spider often attempts to escape rather than bite, unless
it is guarding an egg mass or if it is cornered and pressed. The
male black widow will not bite you. After mating, the female sometimes
eats the male (remember, she only has to mate once in her life),
earning the name "widow." During the period shortly
following mating and laying of eggs, the female black widow can
be a little cranky and hungry. After this period (if he lives
through it!) the male lives quite comfortably, eating prey captured
by the female. The development of his venom sacs stop and become
inactive as the male matures, thus making him less of a potential
problem than his female counterpart.
The bite of the female black widow spider may not always be felt
at first and besides slight local swelling, there is usually little
evidence of a lesion. Two tiny red spots can sometimes be observed
in the center of the swollen area. Most of the time, pain at the
site of the bite occurs immediately and becomes most intense after
about three hours. An overall aching of the body, especially the
legs, are common reactions. Headache, elevated blood pressure,
nausea and profuse perspiration may occur in severe cases. The
condition is self-limiting and in most cases symptoms disappear
in two or three days. Calcium gluconate is used intravenously
to relieve and relax muscle spasms produced by black widow venom.
Be very careful when working around areas where black widow spiders
may be established. Take proper precautions, wear gloves and pay
attention to where you are working. Black widow bites are sharp
and painful, and the victim should go to the doctor immediately
for treatment.
Wolf Spiders
Wolf
Spiders are large, hairy spiders that hunt for their prey by running
it down and capturing it. Although VERY scary they are harmless
and can be ignored.
Sac Spiders
Sac
Spiders are very small spiders with irregular webs and small egg
sacs. These spiders are poisonous and should not be allowed to
multiply inside the home.
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