Brown
Recluse
This spider
has a light brown body and legs. The cephalothorax (head united with
thorax) has a darker brown violin-shaped mark on the upper side. The
female constructs an irregular web outdoors and indoors in undisturbed dry
locations such as basements, garages, closets, and farm outbuildings. The
web is not usually used to trap insect prey. Instead, the brown recluse is
a hunter, emerging from its hiding place at night in search of small
insects for food. Favorite hiding places are in seldom-used clothing
hanging in dark closets, in boxes of magazines, papers and other stored
items, on the underside of furniture, in cracks and spaces around
baseboards, around window and door facings, and in dark cellars and
garages.
Another good image. Check out this close up of
a recluse spider caught on an
"Insect Monitor"
Most victims are bitten after
they put on clothes stored in a secluded closet or that have been lying on
the floor, when cleaning closets or storage areas, or when they roll on a
spider while in bed. Initially, there may be little or no pain from a brown
recluse bite, but over the course of several hours, an intense localized
pain develops, followed by inflammation of the area. Within a few days, a
large ulcerous sore forms around the bite. This sore heals very slowly and
leaves a large disfiguring scar. There is no specific anti-venom available
for brown recluse toxin, but various other treatments are used to promote
healing. Early diagnosis and treatment are essential to alleviate pain and
speed healing of ulcerated tissue. It can be important to know what spider
caused the spider bite to assist with an early diagnosis and treatment.
Without a specimen, there is really no way to determine what spider caused a
spider bite, but medical personnel assume that if the bite becomes ulcerous,
it is the bite from a brown recluse spider. If your home is in the Memphis
area don't hesitate to phone us for more information on a special service
for the recluse spider, hobo spider, or any other pest.
SPIDERS
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Black Widow
photo by M.S. Lacey |
Brown
Recluse
photo by M.S. Lacey |
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Hobo Spider
photo by M.S. Lacey |
COMMON NAME:
Spiders
SCIENTIFIC NAME:
Various
CLASS/ORDER/FAMILY: Arachnida/Araneae/Various
METAMORPHOSIS: Simple
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INTRODUCTION.
There are over 38,000 species of spiders worldwide, with about 3,500
occurring in North America. Many species of spiders are household pests.
Wherever their food is available; spiders are likely to be found. All
spiders are predators, feeding mainly on insects and other small arthropods.
In the United States, three spider groups are considered medically
important: the black widow, brown recluse, and Hobo spiders.
RECOGNITION.
Non-insect arthropods with 2 body regions, cephalothorax (head and thorax)
and abdomen connected by a tiny waist (pedicel). Antennae absent. Usually 8
simple eyes, occasionally 6. Below eyes are 2 chelicerae or jaws which end
in a hollow fang, connected internally to poison glands. With 1 pedipalp (palp)
between chelicerae and 1st pair of legs on each side. Legs slender, 4 pairs.
Abdomen unsegmented, with a group of fingerlike spinnerets (produce silk) on
posterior or rear end. Males usually smaller than females and with terminal
pedipalp segment greatly swollen, may also differ in coloration. The
immature stages are egg and spiderlings, the latter closely resemble the
adults except for size and sometimes coloration.
IDENTIFICATION.
Since black widow, brown recluse, and Hobo spiders are of primary importance
in human environments, their identification is essential. Several different
species may be involved and which can only be identified by experts.
However, group recognition alone is sufficient for the purposes here.
Black Widow.
Adult female body length about ½" including an almost spherical
abdomen about ¼-3/8" in diameter, with overall length including legs
of about 1 ½ - 1 3/3"; males about half female size. Color typically
black, abdomen on underside with 2 reddish triangular markings usually
joined to form a reddish hourglass-shaped marking but sometimes separated (“split
hourglass”) or only a single mark; usually with red markings above
spinnerets.
Brown Recluse.
Adults usually about ¼ - ½" in body length. Color tan to dark brown
with a darker fiddle-shaped marking on top of cephalothroax whose neck
points towards abdomen. Uniquely, with 6 eyes arranged in 3 groups of 2 (diads)
in a semicircle. Found primarily in southern states.
Hobo Spider.
Adult female body length about 7/16 - 5/8" including oblong abdomen,
male body length about slightly smaller. Total size including legs about 1-1
¾" in diameter. Color variable with carapace (top of cephalothorax)
light to medium brown, with dark stripe to either side of lighter midline
stripe, dark stripe with lateral extensions in posterior half; abdomen with
interrupted light midline stripe with about 5 light colored triangular
shaped loops on each side bordered by a dark background. Last 2 or 3 loops
chevron-shaped. Found only in the northwest United States.
BIOLOGY.
After mating, females produce egg sacs. Depending on the species, one or
more sacs may be made. Early instars (spiderlings) spin a silk thread into
the air and float out on the breeze like kites. This is called ballooning
and provides for general dispersal of the species. Spiderlings go through 4
- 12 molts before maturity. Most spiders live for 1 to 2 years. Spiders are
predators, paralyzing or killing their pry with venom. They typically feed
by injecting a predigestive fluid into the body of their pry and then suck
in the digested liquid food. Spiders can survive without food for several
weeks to a few months. Most spiders are nocturnal and hunt or capture prey
primarily at night. During the day, they hide and remain inactive in cracks
and crevices. Spiders rarely bite people and only do so as a means of
defense.
CONTROL.
Spider control is a multi-step process.
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Inspection.
A thorough inspection of the building is essential and many have to be
made at night because most spiders are nocturnal.
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Identification.
Accurate identification is important for both pest management and
medical reasons.
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Prevention.
This consists of making sure that the building is in good physical
condition, and properly screened and sealed to reduce entry. Also,
changing the lighting to off-building locations, from mercury vapor to
sodium vapor lamps, or in the case of homes, changing the bulbs near the
entrances to yellow bulbs, may be of help in reducing attractiveness to
insects and hence spiders.
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Sanitation.
Such practices consist of keeping the premises free of debris such as
boxes, papers, clothing, lumber piles, etc; it is wise to wear
protective gloves and clothing when cleaning out such accumulations of
clutter. A thorough housekeeping should be done twice each year.
Outside, remove debris, firewood and lumber piles, landscape timbers,
stones, etc. Keep the grass mowed to 3” or less and trim back any
vegetation in contact with the structure.
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Mechanical
measures. The key to control is the timely mechanical removal of spiders
and webs, but especially the egg sacs with a vacuum, both inside and
outside; seal and dispose of the bag immediately. If a broom is used for
the removal, then it is suggested that if a spider is present on the web
that an appropriately labeled insecticide be used for a quick contact
kill before removal of the web.
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Pesticide
application. If desired, chemical control consists of the application of
appropriately labeled dusts, wettable powders, microencapsulated, or
lacquer pesticides in typical spider harborages. Perimeter treatments
are helpful. If web-building spiders are the problem, lightly dusting
the web with a non-repellent dust is very effective. Control of spider
insect food is desirable but will only help in long term as spiders can
go for weeks or months without food.
Call for an estimate & details on the
correct treatment procedures
If your problem is minor or all you need is a monitoring trap, go to http://www.critterridders.com/spiders_traps.htm
. The insect traps (monitors) is a great tool for this task and a simple
procedure for the homeowner. However, you do not want to substitute this
as your only approach if you have a serious infestation. If your home is
in the Memphis area don't hesitate to phone us for more information on a
special service for the recluse spider.
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