Pest Information

Desert Recluse Spider

Desert Recluse Spider

  • Latin Name: Loxosceles deserta
  • Common Name: Desert Recluse Spider
  • Other Names: Brown spiders, Fiddleback spiders

Pest Details

Desert Recluse Spider
Desert Recluse Spider

Origin:

This is a native species in the southwest U.S.

Biology:

This uncommon spider is found in the desert environments of the Mojave and Sonora Deserts in California, Nevada, and Arizona and stretching into Utah. It is rarely found around urban areas with irrigated landscape, preferring to stay in natural areas where it often may live within rodent burrows or packrat dens where insects may be encountered as food. Recent opinion from the University of California suggests that the venom of this species should be considered equal in potency to that of the Brown Recluse, but this remains unproven. The venom is, however, capable of causing skin disruption and lesions but for 90% of proven victims of a bite the wound heals quickly and without scarring.

Identification:

The ideal character that is distinctive for the Loxosceles spiders is the arrangement and number of eyes. They have only 6 eyes, whereas most other spiders have 8, and the 6 eyes are arranged as 3 pairs in a wide arc across the top-front of the head. There also will normally be a darker “violin” shaped pattern on top of the cephalothorax, with the widest part at the front. The overall color is brown to dark brown, the legs are very long and relatively hairless, and with legs spread outward the spider may have a diameter of less than 1.5 inches. The cephalothorax is round in appearance and the abdomen is narrower and covered with very short hairs that give it a dull look.

Characteristicts Important to Control:

As with most spider control habitat modification is important, removing or elevating all materials on the soil that might serve as a hiding place and moving firewood and other unnecessary materials away from the structure. These are hunting spiders that do not spin webs for the capture of food. A good program of exclusion should take place to permanently close all openings the spiders may use for entry to structures. The use of a labeled residual, contact insecticide around doorways and windows, entry points, and into possible harborage will help to kill the spiders. This species is not likely to take up residence within a structure.

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