Interesting Notes About The Brown Recluse Spider

By Faith Oi, University of Florida, and Gary Mullen, Auburn University; ACES publication

Description

The brown recluse spider belongs to a group of spiders commonly known as the "fiddle-back" spiders because of the violin-shaped marking they have on their cephalothorax (fused head and thorax). The shape and intensity of the fiddle design may vary. Most spiders have four pairs of eyes. The brown recluse has only three pairs of eyes, arranged in a semicircle on the front of the cephalothorax. These spiders are pale tan to brown in color. Female bodies range in size from 10 to 15 mm (about 1/4 to 1/2 inch) and have a leg span of over 25mm (1 inch). Males are generally half the size of females.

Distribution, Habitat and Habits

The brown recluse spider has been collected throughout Alabama but is more commonly found in the northern half of the state. It is commonly found indoors in storage areas such as closets, basements and cellars. The spiders take shelter in boxes, stored clothing , shoes, under furniture, folded bedding and any other areas of clutter where it is dry and warm. Brown recluse spiders are adaptable. They are active in temperatures ranging between 45 and 110 degrees F, can survive long periods without food or water, and may live for up to 2 years. They generally are not aggressive. Humans are usually bitten when they inadvertently roll onto a spider during their sleep or put their foot in a seldom worn shoe inhabited by a brown recluse.

Bites

Bites occur year-round in heated homes where the temperature remains constant. When a brown recluse bites, it injects cytotoxins that cause tissue death or necrosis of the bitten area. Many brown recluse spider bites go unnoticed initially or result in mild stinging. Some people may feel a burning sensation within 30 minutes after the bite. Then, within 8 hours, a necrotic spot may develop which can enlarge to the size of a silver dollar. If these symptoms do not appear within 48 to 96 hors, necrosis is not likely. If these symptoms do appear, the area can become ulcerated an sunken. lesions may take months to heal.

Treatment

First aid for someone who has been bitten by a brown recluse spider includes use of an ice pack to prevent or to reduce the swelling in the area where the bite occurred. Also, sanitizing the area with hydrogen peroxide or alcohol helps to prevent infection. Promptly seek medical attention. If the spider can be found, it should be collected and taken with the patient to the doctor to confirm the identity of the spider involved.