BlogHow to Identify a Brown Recluse Spider

The Brown recluse spider (Loxosceles reclusa) has quite a reputation. Recluses possess a necrotic venom that can rarely trigger severe or even life-threatening symptoms in bite victims. To make matters worse, the spider is relatively common in the central and southern US. After learning about the Brown recluse, lots of people start imagining them everywhere. No matter how rare Brown recluse spider bites are (very), just the possibility is enough to freak you out. That’s why we put together this guide on how to identify a Brown recluse for sure. Next time you think you see a recluse, check for each of the following elements:

Uniform Coloration

Brown recluse spiders range in coloration from light, tan-brown to a darker, dirt-like brown. Their legs will be a slightly lighter version of the same color as their bodies. Most importantly, this color is mostly uniform. Although their heads may be a slightly different color than their bodies, Brown recluse spiders largely mono-colored. Except for a single, small dark mark on their abdomen (we’ll get to that), they have no stripes, bands, or mottling. If the spider you’re looking at has stripes or bands, it’s not a Brown recluse. If you’re not completely sure, check the legs. Many spider’s legs have multi-colored banding or speckled pigmentation, but Brown recluse legs do not. Likewise, other spider’s legs are frequently darker than their bodies, not lighter. Brown recluse spiders come in a couple different colors, but they’re always basically one color. If you see a multi-colored spider, then it’s probably not a Brown recluse.

“Violin” Mark

All Brown recluse spiders have a single “violin-shaped” mark at the top of their cephalothorax (fused head and thorax). This mark varies in size and intensity, but it’s always darker than the spider’s body. The mark is broadest at the top of the spider’s head, behind its eyes. This part is the “body” of the violin. As the mark runs toward the abdomen, it tapers off. That’s the “neck” of the violin. The specific shape and color of the violin mark varies from spider to spider. It may not look exactly like a violin, or may be almost too small to see. Young Brown recluse spiders may not have developed their mark yet. If the marking is lighter than the spider’s body, then it’s definitely not a Brown recluse. Likewise, if the spider has markings on its abdomen (not its cephalothorax), then you can count Brown recluse spiders out.

Eye Pattern

Almost all spiders have eight eyes, but Brown recluse spiders only have six. These eyes are arranged in three pairs of two. The two pairs on the sides of the spider’s head are slightly higher. The pair in the center is slightly lower. Brown recluse spider’s eyes are very small and black, so they may be difficult to see. Other spiders have the same eye structure, but they don’t also have the recluses’ violin mark and color uniformity. Obviously, we don’t recommend getting too close to the spider you’re identifying. Brown recluse eyes can be difficult to see. If you’re very worried about the spider, or it’s already bitten you, attempt to trap it before examining it. You could also examine it once it’s dead. If the spider bites you, we recommend catching and trapping it. Show it to your doctor or pest expert. We’ll be able to positively identify it for you using a magnifier.

Fine Hairs, Not Spines

Most spiders, including common house spiders, have large “spines” on their legs and abdomens. These spines are actually thick, modified hairs that cover the spider’s limbs and help spiders hold their prey. Unlike most spiders, Brown recluse spiders do not possess these “spines.” Instead, they’re covered in many short, fine hairs. These hairs are small and difficult to see, making them easy to tell apart from spines. Like their coloration, a recluse’s hair is also uniform throughout their body. If you look closely, you’ll be able to see hair growing everywhere except the spider’s head. Conversely, if you notice long or matted-looking hair, then the spider isn’t a recluse. Recluse hair is short because they don’t use it to ensnare prey, the way spined spiders do. Check the spider’s legs for spines. If they seem to have them, then it isn’t a Brown recluse. ‌ To summarize: the Brown recluse spider is a small (¼ to ¾ inches) spider. It has uniformly tan or brown coloration and a single brown violin mark near its head. Unlike most spiders, it has six eyes, not eight. It’s covered in fine hair, but it doesn’t have spines. If your spider possesses each of these characteristics, it might be a Brown recluse. If it’s missing any, then it’s not. If you’re concerned about Brown recluse spiders in your home, we don’t blame you! Instead of panicking, however, just give Plunkett’s a call right away. We’ll be able to help drive the spiders in your home away--whether they’re Brown recluse spiders or not!