The brown recluse spider (Loxosceles spp.) is a poisonous spider that is light brown in color. It is about 1/2 inch in length, 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. These spiders make an irregular and sticky web that is used for shelter rather than for trapping insects.
There are seven species of brown recluse spider that are a health concern in the United States. 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. Bites often occur when the spider is trapped in shoes or clothing, rolled on while in bed, and encountered when cleaning storage areas.
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 bite is not usually felt, but a stinging sensation may develop shortly after, followed by intense pain. The reaction, however, 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.
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.