Chilean recluse spider

Chilean Recluse Spider

The Chilean recluse spider (Loxosceles laeta), one of the most venomous spiders in the Loxosceles genus, is notorious for its necrotic bite. Native to South America, particularly Chile, it has been found in other parts of the world due to human activities. This spider is a significant concern due to its potent venom, which can cause serious medical conditions.

Description

The Chilean recluse spider is typically light to medium brown, with a body length of about 8 to 15mm for males and 9 to 18mm for females. One of its distinguishing features is the presence of a violin-shaped marking on the dorsal side of its cephalothorax, leading to the nickname "fiddleback spider" or "violin spider". However, this marking is not unique to Loxosceles laeta and can be found on other recluse spiders.

Habitat

Originally from South America, the Chilean recluse spider has been introduced to various parts of the world, including North America and Europe. It prefers dark and undisturbed places, such as basements, closets, and woodpiles. In their natural habitat, they are found under rocks and logs.

Behavior

Chilean recluse spiders are nocturnal and tend to avoid human contact. They are not aggressive and usually bite only when pressed against human skin. Bites often occur when putting on clothes or shoes that a spider has crawled into.

Venom

The venom of the Chilean recluse spider contains a complex mix of enzymes, including sphingomyelinase D, which is responsible for the necrotic lesions and systemic reactions observed in severe cases of envenomation. Symptoms of a bite can range from mild skin irritation to severe necrotic lesions and systemic conditions such as hemolysis, thrombocytopenia, and acute renal failure.

Medical Treatment

Immediate medical attention is crucial for suspected bites from a Chilean recluse spider. Treatment may involve cleaning the wound, pain management, and in severe cases, surgical intervention to remove necrotic tissue. Antivenom is available in some regions but its use is controversial due to concerns about efficacy and adverse reactions.

Prevention

Preventive measures include reducing clutter, sealing cracks and crevices in buildings, and checking clothing and bedding in areas where the spiders are common. Use of insecticides can also help control spider populations.

See Also

• Spider bite
• Necrosis
• Venomous spiders