Brown Recluse Spider

Loxosceles reclusa

The brown recluse spider, also known as the "violin" or "fiddleback" spider, is one of the most poisonous spiders in North America. It is native to the United States, and is most often seen in the central and southern Midwest. It is also a commonly misidentified spider. This is due to the large amount of fear surrounding the brown recluse. When people fear a given spider species, they are then more likely to suspect it when trying to identify something crawling on their ceiling at night.

Identification Guide

As mentioned above, the brown recluse is a commonly misidentified spider. Some of the basic attributes of the brown recluse are fairly universal among spiders. Its brown, the body is about 1/2 inch full grown, and has markings which are similar on other common spiders. However, if you look closely at the brown recluse and compare it to similar spiders, the differences are obvious.

• Primary Colors: A brown recluse is primarily brown. This can vary from a light brown or tan, to dark brown.
• Body Characteristics: The abdomen on a brown recluse spider is for the most part a solid brownish color. It will appear velvety, and smooth due to tiny dense hairs. The only discoloration you may see would be a darker line running vertical down the center of the abdomen. This is the spider's heart. The cephalothorax (head) has the violin, or fiddle shaped marking which always "points" towards the abdomen.
• Legs: The legs on a brown recluse are covered with tiny hairs, not spines. The legs also do not have bands or stripes, which is often seen on misidentified brown recluses. See pictures of the Green Lynx for a good example of a spider with impressive spines.
• Markings: The violin or fiddle shaped marking on the spider's head is the most famous identifying characteristic. Keep in mind that there are many other spiders which have similar markings which can appear on the head or abdomen. The brown recluse is not unique in this attribute, however it does help quickly narrow down your options when attempting to identify a spider with this mark in the United States.
• Eyes: The brown recluse has 6 eyes instead of 8, arranged in 3 pairs of 2. The majority of spiders have 8 eyes, usually arranged in two rows of 4. It is extremely hard to identify how many eyes the brown recluse has, even if you have great camera equipment.
• What to remember: The brown recluse is not alone with violin-style markings. However, all of the following variables must be met in order for likely positive identification. A smooth, uniformly colored abdomen. A marking of a violin or fiddle on the cephalothorax pointing to the abdomen. Uniformly colored legs that have NO spines, and no stripes or extreme variation in color.

Habitat and Spider Web

As the name suggests, the brown recluse spider is a non-aggressive, reclusive spider that seeks out dark undisturbed areas and is usually found indoors. It is rare to see them outdoors, but brown recluses may be seen in lumber piles or under rocks and logs. Indoors, they occupy areas like attics, basements, sheds and barns, undisturbed clothing, shoes, cardboard boxes, and behind furniture. While it does create a web, which is atypical and rather random in design, this web is not used for catching prey, but solely as a home or shelter. Instead of catching prey in its web, the brown recluse roams around hunting for insects when feeding. Research suggests that it is more of a scavenger, preferring dead insects as opposed to hunting live ones.

Brown Recluse Spider Bite and Venom

Spider Identification.org is a site dedicated towards identifying and archiving spider information, and pictures. Therefore, we will not cover brown recluse spider bites in great detail, or offer specific treatment advice. The brown recluse is not an aggressive spider, and bites generally happen when someone accidentally disturbs them. Often times a bite happens when putting on an occupied shoe, rolling over onto a brown recluse while sleeping, or reaching for a piece of lumber in your shed. Brown recluse venom generally causes necrosis, causing the tissue in the surrounding area to die, creating a sore. These spider bites rarely cause serious problems. The very young, and the elderly are the most effected and can have the more serious symptoms. Please consult a physician with specific questions, and concerns regarding brown recluse spider bites.

For more specific information on brown recluse spider bites, we recommend the following sources.

emedicinehealth site - Provides detailed information on brown recluse spider bites, symptoms, treatment, and mortality statistics.