Brown Recluse (Violin Spider)

Brown recluse_07.jpg

Closeup of brown recluse spider on floor.

MDC staff

Venomous

Family:

Loxoscelidae (venomous six-eyed spiders) in the order Araneae (spiders)

Description:

The name “violin spider” describes a characteristic marking on the brown recluse: there is a violin-shaped patch on the broad, almost heart-shaped cephalothorax (the head, as opposed to the abdomen). The overall color is usually a grayish-yellow-brown, the oblong abdomen covered with gray hairs. The legs are darker than the body and are long and slim. Females are larger then males. The webs are small, irregular, and untidy. These spiders are usually seen walking or running around, not in a web.

Size:

Length: females to ¼ inch, not counting legs; including legs in a typical pose, they are about 1 inch long.

Habitat and conservation:

The name “recluse” describes this spider well. It commonly hides in little-used drawers, closets, attics, and basement areas, and behind baseboards and furniture. They cannot climb smooth surfaces and are often found trapped in bathtubs and sinks. Their habit of hiding among packed-away garments and towels creates a common situation for human bites, when a person dons clothing from storage without inspecting or shaking it out first. In nature, they live under and in crevices of rocks.

Foods:

In diet, brown recluses are little different from other spiders. They eat small insects and other spiders. As a running spider (not a spider that uses webs to catch prey), a recluse chases down prey like a wolf. The purpose of their venom is to subdue their prey. In fact, brown recluses cannot easily bite humans unless they are pressed against our skin (as when they are suddenly trapped between a garment and our bodies, or if they are exploring our bed sheets and we roll on top of them).

image of Brown Recluse Violin Spider Distribution Map

Distribution in Missouri:

Statewide. Though it has a southern distribution naturally, this species has gradually spread northward and is now presumed to occur statewide, indoors.

Status:

Common. Because of their nocturnal and reclusive nature, they are rarely seen, but when you see one, there are probably many more. Their secretiveness is helpful in a way, because their shyness minimizes our encounters with them. If you think you have a brown recluse problem in your house, call an exterminator for advice. Because spiders walk on tiptoes, they generally have little contact with pesticides. Also, eliminate long-neglected, undisturbed, unused storage areas in your home.

Life cycle:

Brown recluses do not live in webs but lead a nomadic hunter’s life and can live for several years. When bitten, humans rarely notice at first, but swelling, redness, and tenderness may occur at the site within about 8 hours, sometimes followed by chills, nausea, or fever. Several days later, the skin at the bite may ulcerate, forming a deep open wound that is slow to heal and susceptible to infection. If you experience such a wound, see a doctor. Death from brown recluse bites is very unlikely.

Human connections:

Though the bites of brown recluses are almost never fatal, they can be disfiguring. Pets can suffer from recluse bites, too. The exterminating industry is built in large part upon the presence of brown recluses and other undesirable creatures in and around our homes.

Ecosystem connections:

Like all spiders, in the wild, brown recluses help decrease the populations of insects and other spiders. They do this also within the “habitat” of our homes, where they consume many of the other creepy-crawlies that hide in our basements, closets, and attics and behind bookcases and furniture.