Brown Recluse Spiders

The Brown Recluse spider, Loxosceles recluse, is a well-known member of the family Sicariidae (formerly placed in the family “Loxoscelidae”). It is usually between 6-20 mm (¼ in and ¾ in) but may grow larger. It is brown and sometimes an almost deep yellow color and usually has markings on the dorsal side of its cephalothoraxes, with a black line coming from it that looks like a violin with the neck of the violin pointing to the rear of the spider, resulting in the nicknames fiddle back spider, brown fiddler or violin spider. Coloring varies from light tan to brown and the violin marking may not be visible.

Habitat

Recluse spiders build irregular webs that frequently include a shelter consisting of disorderly threads. These spiders frequently build their webs in woodpiles and sheds, closets, garages, cellars and other places that are dry and generally undisturbed. They seem to favor cardboard when dwelling in human residences, possibly because it mimics the rotting tree bark that they naturally inhabit. They also go in shoes, inside dressers, in bed sheets of infrequently used beds, in stacks of clothes, behind baseboards, behind pictures and near furnaces. The common source of human-recluse contact is during the cleaning of these spaces, when their isolated spaces suddenly are disturbed and the spider feels threatened. Unlike most web weavers, they leave these webs at night to hunt. Males will move around more when hunting while females don’t usually stray far from their web.

Brown Recluse Spider Distribution

The Brown Recluse spider is native to the United States from the southern Midwest south to the Gulf of Mexico. The native range lies roughly south of a line from southeastern Nebraska through southern Iowa, Illinois and Indiana to southwestern Ohio. In the southern states, it is native from central Texas to western Georgia. They are generally not found west of the Rocky Mountains. A related species, the brown violin spider (Loxosceles rufescens), is found in Hawaii. Despite many rumors, the Brown Recluse spider has not established itself in California or Canada. There are other species of Loxosceles native to the southwestern part of the United States, including California, that may resemble the Brown Recluse, but these species have never been documented as medically significant.