Brown Recluse

The brown recluse, is a spider with a necrotic venom and is one of two spiders (the other being the black widow) with medically significant venom in North America.

Brown recluse spiders are usually between 6 and 20 millimetres (0.24 and 0.79 in), but may grow larger. While typically light to medium brown, they range in color from whitish to dark brown or blackish gray. The cephalothorax and abdomen are not necessarily the same color. These spiders usually have markings on the dorsal side of their cephalothorax, 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 fiddleback spider, or violin spider.

Adult brown recluse spiders often live about one to two years. Each female produces several egg sacs over a period of two to three months, from May to July, with approximately fifty eggs in each sac. The eggs hatch in about one month. The spiderlings take about one year to grow to adulthood. The brown recluse spider is resilient and can tolerate up to six months of extreme drought and scarcity or absence of food.  Recluses prefer to inhabit undisturbed areas, such as attics, crawl spaces, basements, closets, areas under furniture and inside wall voids.  Male recluse spiders and juveniles are most often seen. Females generally stay well hidden, making them more difficult to eliminate.  Due to their reclusive nature and sometimes inaccessible habitats, the control of the brown recluse is a difficult task requiring much effort.

Prevention Tips

Placement of glueboard insect monitors are most effective way to keep foraging spiders under control.

Residual insecticide applications to interior voids and cracks and crevices and exterior perimeter also useful.

Routine cleaning of seldom disturbed spaces such as under furniture, in closets, basements and attached garages can help eliminate hiding places for these spiders.

Keep laundry off of the floor, remove bed skirts and shake out shoes and clothing before use to help prevent bites.

Keep all storage items in thoroughly sealed containers to eliminate habitat