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Venomous Texas Spiders
Venomous Spiders in Texas
Texas has two venomous species of
spiders, the black widow (
Latrodectus mactans) and the brown recluse
(
Loxosceles reclusa). Both of these species of spiders can be found
indoors and outdoors through out the State. The female black widow can be
identified by its jet black color, globular abdomen with a reddish or yellowish
hourglass on the underside. Male, black widow spiders are smaller, brown and
nondescript. The black widow spider is aptly named because the female usually
eats the male after mating. The venom of the black widow is a neurotoxin and can
lead to severe systemic reactions and in rare cases, death. The black widow's
venom is reportedly 15 times more toxic than the venom of the prairie
rattlesnake. However, only a minute quantity is injected with each bite. The
most severe reactions occur in children and older adults. Black widow spiders
can frequently be found in woodpiles, boxes, outdoor toilets, meter boxes, under
eaves, and other undisturbed areas.
Brown recluse spiders
are golden brown in color and can be identified by the characteristic dark brown
to black fiddle-shaped pattern on the head region. Brown recluse venom has
necrotizing enzymes that generally cause local or systemic reactions. These
spiders commonly live in basements and garages of houses and can be found hiding
between boards, boxes, and old towels and clothes in dark, undisturbed areas.
Neither the black widow nor the brown recluse spiders are aggressive but they
will both bite when accidentally trapped, disturbed or threatened.
Symptoms of Envenomization by Spiders
The severity of a victim's reaction to any spider bite depends
on the area of the body bitten, the amount of venom injected, depth of the bite,
the victim's age, and other factors. Additionally symptoms usually differ
between black widow bite victims and brown recluse bite victims. Many times, the
bite of a spider feels like a pin-prick and may not be noticed by the victim.
General Black Widow Spider Envenomization Symptoms- abdominal cramping
- abdominal rigidity
- convulsions
- headache
- lesion at site of bite
- nausea
- pain
- profuse sweating
- tremors
- unconsciousness
- vomiting
General Brown Recluse Spider Envenomization Symptoms- chills
- fever
- nausea
- necrosis at the bite site
- nothing
- red white and blue lesion at the bite site
- restlessness
- weakness
First Aid for Spider Bite Victims
Antivenom is generally not prescribed for black widow
envenomizations. Although an antivenom for the black widow is available, it has
a high probability of an anaphylactic reaction and is used only in extreme
cases. There is no effective antivenom available for brown recluse
envenomization victims. All spider bites posses the potential for a secondary
infection and should be washed thoroughly with soap and water or an antiseptic
if available. If possible, the spider should be captured for positive
identification. An Ice pack may be applied to alleviate pain and swelling in the
bite area. First Aid is of limited help so you will need to contact the Texas
Poison Center Network at 1-800-POISON-1 (1-800-764-7661) or your family
physician for information about treatment. In severe cases, where the victim has
systemic reactions, the victim may be hospitalized and the physician may
administer cortisone-type hormones, muscle relaxants, or pain relievers.
Spider Bite Prevention
Prevention is the best treatment of all for spider bites.
Several chemical and non-chemical controls are available for reducing the risk
of being bitten by spiders in general.
Non-Chemical Spider Control- Eliminate or reduce bright outdoor lighting that attracts insects (spiders'
food supply).
- Trim weeds and grass from around buildings and remove debris to discourage
insects and spiders from living close by.
- Seal or caulk outside openings that may allow spiders to enter the house.
- Use a vacuum cleaner to remove spiders, webs, and egg sacs from inside the
house.
- Wear gloves and watch carefully when in areas where spiders are likely to
live.
- Shake out shoes, clothes, towels, linens, etc. which have been stored and
undisturbed for long periods of time.
Chemical Spider Control- Have a professional apply a residual pesticide around the perimeter of the
building. Over the counter pesticides are often not strong enough to effectively
control spiders.
- Contact pesticides may also be used indoors. However strict attention should
be given to the manufacturer's label and all warnings and precautions observed.
It may be best to have a professional apply more effective pesticides approved
for indoor use.
More Information
Texas Department of State Health Services - Infectious Disease
Control Unit
1100 West 49th Street, Suite T801, Mail Code: 1960 PO BOX
149347 - Austin, TX 78714-9347
(512) 458-7676 - Fax: (512) 458-7616 -
E-Mail
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