Characteristics of Brown Recluse Spiders

Brown recluse spiders (Loxosceles reclusa) are small to medium in size, measuring 6 to 11 mm body length when full grown. At the widest leg span, their bodies are roughly the size of a United States quarter.

Adult specimens vary in color from dull yellow to tawny, dark brown. Younger spiders are lighter in color than adults. The abdomen of the brown recluse has no stripes or spots. They have six eyes, which are arranged in pairs known as dyads.

The most telltale characteristic of brown recluse spiders is the presence of a dark, violin-shaped mark on the dorsum of the arachnid’s light brown or yellowish-brown cephalothorax. The neck of this distinct violin pattern is directed toward the abdomen. Due to this marking, brown recluses are also commonly known as fiddle-back spiders. To positively identify a spider as a recluse, both the eyes and fiddle marking must be seen, since other spiders may possess one or the other characteristic alone.