Brown recluse spider

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Species of spider

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Brown recluse spider
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Arachnida
Order:	Araneae
Family:	Sicariidae

The brown recluse spider (Loxosceles reclusa) is a species of spider in the family Sicariidae. It is native to the United States, particularly in the Midwest and South. The brown recluse is known for its necrotic venom, which can cause significant medical issues in humans.

Description

The brown recluse spider is typically light to medium brown, with a characteristic dark violin-shaped marking on its back. The spider's body length ranges from 6 to 20 millimeters, but it can appear larger due to its long legs. Unlike most spiders, the brown recluse has six eyes arranged in pairs (dyads) with one median pair and two lateral pairs.

Habitat

Brown recluse spiders prefer warm, dry environments and are often found in human dwellings. They commonly inhabit basements, attics, and garages, as well as outdoor areas such as woodpiles and sheds. The spider is nocturnal and tends to avoid human contact, hence the name "recluse."

Behavior

Brown recluse spiders are not aggressive and typically bite only when threatened or disturbed. They are known for their reclusive behavior, often hiding in dark, undisturbed areas. The spider's diet consists mainly of small insects and other arthropods.

Venom

The venom of the brown recluse spider contains a complex mixture of enzymes, including sphingomyelinase D, which can cause severe tissue damage. Bites from the brown recluse can result in necrosis, leading to open sores and, in severe cases, systemic symptoms such as fever, chills, and nausea. Medical attention is often required for bites, especially if significant tissue damage occurs.

Medical Significance

Brown recluse spider bites can be medically significant, particularly in cases where necrosis develops. Treatment may involve wound care, pain management, and, in some cases, surgical intervention. It is important to seek medical attention if a brown recluse bite is suspected.

Prevention

Preventing brown recluse spider bites involves reducing the likelihood of encountering the spider. This can be achieved by keeping homes clean and clutter-free, sealing cracks and crevices, and using insecticides in areas where spiders are likely to inhabit. Wearing gloves and long sleeves when handling items stored in basements or attics can also reduce the risk of bites.

See also

• Spider bite
• Necrotizing fasciitis
• Venomous arthropods