Brown Recluse Spider

Contact: Eric Day, Manager, Insect Identification Laboratory

August 1996

Brown Recluse Spider

Araneae: Loxascelidae, Loxosceles reclusa

SIZE: 1/4 to 3/4 inch (6.4-19.1mm)

COLOR: Golden brown

DESCRIPTION: Brown recluse spiders belong to a group of spiders commonly known as violin spiders or fiddlebacks. This is because of a characteristic fiddle-shaped pattern they have on their head region. The spider is golden brown with the fiddle being dark brown or black. This spider is not hairy and the fiddle pattern is often shiny. They are about 1/4 to 3/4 inch long.

HABITAT: Brown recluse spiders are found primarily in the Midwest. Many cases of bites are reported from Texas, Kansas, Missouri, and Oklahoma. The edge of its range just reaches the tip of western Virginia, but it occurs rarely in this state. The spider commonly lives in basements and garages of houses and often hides behind boards and boxes. Bites often occur when the spiders hide in towels or old clothes left in those areas.

LIFE CYCLE: Female 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.

TYPE OF DAMAGE: The severity of the bite may vary. The symptoms may vary from no harm at all to a reaction that is very severe. Often there is a systemic reaction within 24-36 hours characterized by restlessness, fever, chills, nausea, weakness, and joint pain. Where the bite occurs there is often tissue death and skin is sloughed off. In some severe cases, a wound may develop that lasts several months.

CONTROL: In all cases, a physician should be notified. If at all possible, kill and take the spider to the physician for positive identification. Individual spiders can be crushed underfoot or sprayed with an aerosol spray. Clean up and remove any potential hiding places.

Important note: Many of the wolf spiders are similar in appearance and have similar markings as the brown recluse. They are large, robust, and hairy and, therefore, can be distinguished from the brown recluse.

INTERESTING FACTS: Spiders are seldom aggressive and bite only when threatened or injured.

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