The brown recluse's six eyes are arranged in pairs in a semi-circular pattern that creates the anterior part of the violin shape, though you would need a good magnifying lens to distinguish them. The tail-end segment of the spider has no markings. A brown spider with markings on the tail end is probably not a brown recluse. Their overall size is 3/8 inch to 1/2 inches. The males are slightly smaller than the females.
Where are Brown Recluse Spiders found?
They are found outside in firewood piles, leaves, or piles of rocks, or indoors in dark closets, shoes, cluttered basements or attics. brown recluse spiders are also called fiddleback or violin spiders. How can I keep Brown Recluse Spiders out of my home and yard?
Recluse Species and Range
There are twelve or thirteen recluse spider species in the United States including the infamous Loxosceles reclusa, the brown recluse, which is most common in the midwestern and south-central states, and the Arizona brown spider, or the desert recluse, which is found in the southwestern desert states.
The violin-like markings on the desert species are less obvious, but the bite, though not usually life-threatening, should be considered dangerous and can lead to severe tissue damage. Recluse spiders have also been reported in areas outside this range, sometimes hitchhiking in luggage or inadvertently sent in packaging.
The Name: Brown Recluse
As the name “recluse” suggests, these spiders are shy. They retreat when possible, and prefer dark, undisturbed places near or on the ground for their webs, which are used for nesting, not for trapping prey. In fact, the typical web seen in visible areas such as a wall or eave is most likely not due to a brown recluse, but to other types of spiders that may even pursue the brown recluse as prey. Brown recluse spiders usually live in dense clusters. Usually where one is found, there will be more. They are scavengers, prefering dead prey to live.
The nocturnal brown recluse spiders hunt for insects some distance from their webs. Contact with humans usually occurs because they have taken temporary refuge in clothing or bedding. Items left lying undisturbed on the floor, such as supplies, toys, or clothing, are perfect daytime refuges for these spiders. Such objects should be shaken out thoroughly if they have been on the floor or in a closet for any length of time.
Behavior
Like undisturbed places for their webs; hunt primarily at night and will take refuge in clothing and bedding; often found in unused closets and storerooms, behind furniture, and in baseboard cracks and crevices. Outside, they can be found in foundation cracks, cracks in the soil, and window wells. The brown recluse spider prefers food such as firebrats, crickets, cockroaches and other soft bodied creatures. Earning their name well, the brown recluse spider ceases its wanderings at first light.
The brown recluse spider is a non-aggressive spider and will only bite when disturbed. Usually, the brown recluse spider bite is not felt and the pain sets in from six to eight hours later. A typical bite area may resemble a pimple, pustule or blister formation from six to 12 hours later. The bites are unpleasant, producing an ulcerous wound called a necrotic lesion that turns dark within a day and takes a long time to heal. See Symptoms of Brown Recluse Spider bite and information on how to treat the bite.
Breeding
The female brown recluse spider deposits eggs in off-white silken cases about 1/3 inch in diameter in sheltered, dark areas. Spiderlings emerge in 24-36 days and abandon the egg case. Development is slow, influenced by weather conditions and food availability. They reach maturity in 10 to 12 months and can survive long periods of time without food or water. Immature spiderlings resemble adult brown recluse spiders but have lighter coloration. Spiderlings will molt several times on their journey to adulthood. Brown recluse spider moltings have a stiff appearance - discovery of this type of spider molting can be a useful indication of brown recluse infestation. Adult males and females will vary from light tan to dark brown.
Common Questions:
Sources:
National Library of Medicine EPA
"BROWN RECLUSE SPIDER," Michael F. Potter, Urban Entomologist, University of Kentucky College of Agriculture, Department of Entomology, University of Kentucky
Pest Notes: Brown Recluse and Other Recluse Spiders
UC ANR Publication 7468
Author: R. S. Vetter, Entomology, UC Riverside
