Brown Recluse



DESCRIPTION

The brown recluse spider (Loxosceles spp.) is a poisonous spider that is light brown in color. The adult body varies from 1/3- to 1/2inch in length, with the arrangement of the legs producing a larger overall size of 1 inch diameter or greater. The body is yellow to dark brown, has a violin-shaped marking on the thorax (mid-section) and is sometimes called a fiddleback spider due to the unique markings.

While most spiders have 8 eyes, the brown recluse has 6 (3 pairs). The brown recluse spider received its name because of its color and reclusive behavior. Recluse spiders are often colored tan, but can be dark brown to almost white in appearance.These spiders make an irregular and sticky web that is used for shelter rather than for trapping insects.

BIOLOGY

There are seven species of brown recluse spider that are a health concern in the United States. The spider has been widely reported in the southern, western, and mid western United States, and is a particularly serious pest in Oklahoma, Missouri, and surrounding states.

It is usually found indoors, particularly in bathrooms, bedrooms, closets, garages, basements, and cellars. In homes with forced hot-air heating and air conditioning and often above-ceiling ductwork, brown recluse spiders are commonly found harboring in or around the ductwork or registers.

They may also be present in attic areas or other locations above the ceiling. They are also commonly found in cluttered closets or basements, and in outbuildings where miscellaneous items are stored. The web is not elaborate and is best described as an off white to gray, nondescript type of webbing. The spider is not aggressive and usually retreats to cover when disturbed.

Most bites occur when a person crushes the spider while putting on old clothes that have been hanging in a garage, or by rolling on the spider while asleep in bed.Though active throughout the year, they often go unnoticed because of their reclusive habits. Adults may be found in dark, secluded indoor places that are dry, cluttered, undisturbed and contain a supply of insects for food.

They are most commonly found behind baseboards, under tables and chairs, in the basement, crawlspace, attic, infesting cedar shake roofs, and in garages and sheds. Another common hiding place for a brown recluse is in garments that are left hanging undisturbed for some time and in the linens of beds that have been unoccupied for a long while.

The brown recluses venom is a cytotoxin that attacks the cells of flesh and produces necrosis or dead tissue in humans. Though fatalities from the venom are very rare, the reaction to the venom depends on the amount of and individual sensitivity to the toxin. The initial pain associated with the bite is not intense, and is generally less troublesome than a bee sting.

The reaction may not occur until an hour or more after the bite. The bitten area will first develop a small, white blister and enlarge to the size of a silver dollar as the venom attacks and kills the tissue in the affected area. Eventually, the affected tissue will die and leave a sunken, ulcerated sore.

The healing process is slow, generally six to eight weeks. If bitten, call a physician or go to the emergency room immediately. If possible, exterminate the spider and take it along for identification purposes. Though no antitoxin is available, prompt medical treatment can prevent severe reaction and minimize the extent of damaged tissue and eventual scarring.

SOLUTION

To avoid getting bitten by the brown recluse, shake out unworn or stored shoes and clothes before wearing, check bed linens of unoccupied beds and wear leather gloves when working around potential habitats. Use caution around spider webs in basements and crawlspaces. If a brown recluse is encountered, contact a pest control professional.

Black Widow

DESCRIPTION

The female black widow spider (Latrodectus spp.) is a poisonous spider that has a somewhat round, shiny black abdomen with red markings that resemble an hourglass on the underside. The size of the body is approximately 1/2 inch wide and 1 1/2 to 1 3/8 inches long. Despite common opinion, the female rarely kills the male after mating.

BIOLOGY

Five different species of the black widow spider are prevalent in North America. They generally live under rocks and under fallen trees outside the home. In and around the house they are often found in firewood piles, basements and crawlspaces. They are also found in secluded places, such as garages and sheds. They feed on insects and other spiders that are trapped in their web.

The widow's web is an irregular mass of fibers with a small central area to which the spider retreats while waiting until its prey becomes ensnared. These webs are frequently constructed underneath boards, stones, or the seats of outdoor privies. They are also found along foundation slabs, behind shrubs and especially where brick or wood siding extends close to ground level.

This spider does not usually enter residences. They are usually not aggressive spiders, but if handled or accidentally touched, they may bite.

Widow spider venom contains toxins that are neurotoxic (affects the nervous system). The black widow's venom is a neurotoxin that attacks the nervous system and may cause pain and serious illness in humans. Though the bite is not often felt, pain will develop immediately.

The severity of a person's reaction to the bite depends on the area of the body where the bite occurs; the person's size and general sensitivity; the amount of venom injected; depth of bite; seasonal changes (in venom potency); and temperature.

The bite produces a sharp pain similar to a needle puncture. The pain usually disappears rapidly. Local muscular cramps are felt 15 minutes to several hours after the bite, spreading and becoming more severe as time passes. The venom then grows weak, tremors develop, and the abdominal muscles show a board-like rigidity.

Respiration becomes spasmodic and the patient is restless and anxious. During this period, a feeble pulse, cold skin, labored breathing and speech, light stupor, and delirium may be noted. Convulsions and death may result with some victims, especially if the person is sensitive to the venom and no treatment is received.

An anti-venom specific for the black or brown widow is readily available to most physicians. Antitoxin is available to combat the neurotoxin. If bitten, call a physician or go to an emergency room immediately. If possible, exterminate the spider and take it along for identification purposes. Bites are rarely fatal when promptly treated, however, small children are at greater risk.

SOLUTION

To avoid getting bitten by the black widow, wear leather gloves when working around potential habitats. Use caution around spider webs in basements and crawl spaces. If a black widow is encountered, contact a pest control professional.