Brown Recluse Spiders
Five species of recluse spiders have been recorded in Alabama: Loxosceles apachae, L. blanda, L. devia, L. reclusa and L. rufescens. Although only L. reclusa and L. rufescens have been recorded as venomous to people, it is best to consider all these species as potentially dangerous.
The best-known species, the brown recluse spider, Loxosceles reclusa, inhabits many Southern and Midwestern states. Recluse spiders are frequently found in garages, firewood piles, cluttered cellars and stored board piles. They often live around human dwellings, in bathrooms, bedrooms and closets, under furniture, behind baseboards and door facings, or in corners and crevices. Recluse spiders are most active at night when they hunt. People are sometimes bitten while asleep, apparently when rolling over on a spider while in bed. Others are bitten when putting on clothes that have hung undisturbed for a long time and where spiders are hiding.
Description and life cycle
As their name implies, recluse spiders are generally shy. They spin nondescript white or grayish webs, where they may hide during the day. They are predators of insects and other arthropods, known to wander around houses looking for prey. While walking, their body and legs together cover an area about the size of a quarter or half-dollar, but the body itself is only 1/4 to 1/2 inch long. Their color varies from orange-yellow to dark brown.
The brown recluse’s most distinguishing characteristics are its eye pattern and markings on the back. Recluse spiders have six eyes arranged in three pairs in a semicircle on the forepart of the head. Uncommon in spiders, this eye pattern helps separate recluse spiders from similar species. The eyes also form the base of a violin-shaped marking on the back. The neck of the “violin” forms a distinct, short median groove (see Figure 1). The violin marking may be conspicuous or blend with the background color. Just because you can't distinguish the "violin" don't assume that the spider is not a brown recluse.
One other group of spiders, the spitting spiders, Scytodes, has a similar eye arrangement. A spitting spider has long, spindly, banded legs and a spotted pattern on its cephalothorax, the front body region. The cephalothorax is raised in spitting spiders but nearly flat in recluse spiders. Slow-moving, spitting spiders are common in window sills and considered harmless.
Brown recluse spiders lay one to two egg masses per year in dark, sheltered areas. Similar to those of many other spiders, recluse egg cases are round, about 5/8 inch (1.6 cm) in diameter, flat on the bottom and convex on top. After 24 to 36 days, an average of 50 spiderlings emerge from the egg case. Their slow development is influenced greatly by nutrition and environmental conditions.
Bite symptoms
The effects of a recluse spider bite may be immediate or delayed, depending on the amount of venom injected and the victim’s sensitivity. Sometimes hardly noticed at first, the bite later causes a stinging sensation that may include intense pain. Fever, chills, nausea, weakness, restlessness and/or joint pain occur within 24 to 36 hours. The bite also produces a small blister surrounded by a large congested and swollen area. The venom usually kills the affected tissue, which gradually sloughs away and exposes underlying tissues. The edges around the wound thicken, while the exposed center fills with dense scar tissue. Healing may take six to eight weeks, often leaving a scar, depending on the amount of venom injected and the reaction of the individual. If you feel that you have been bitten by a brown recluse, it is advised to seek medical attention immediately. This is the best defense against permanent scarring.
