Brown Recluse Garden Spiders 2

IDENTIFICATION The most definitive physical feature of recluse spiders is their eyes: most spiders have eight eyes that typically are arranged in two rows of four but recluse spiders have six equal-sized eyes arranged in three pairs, called dyads. There is a dyad at the front of the cephalothorax (the first main body part to which the legs attach) and another dyad on each side further back. Many publications refer to the violin on the dorsal surface of the cephalothorax as the most important diagnostic feature. Although this marking is fairly consistent in mature brown recluses and Texan recluses (L. devia), it can vary in intensity and sometimes fades in preservative, and it is very faint to nonexistent in several recluse species found in the southwestern United States (e.g., the desert recluse). Therefore, checking the eye pattern will eliminate almost all suspect recluse spiders from consideration whereas the presence or absence of the violin marking may lead to misidentifications. In addition, the abdomens of all recluses are covered with fine hairs and are uniformly colored, although the coloration can vary from light tan to dark brown, depending on what they have eaten. There is never a coloration pattern on the abdomen. Finally, the legs are similarly covered with fine hairs whereas many nonrecluse spiders have stout spines on their legs. Some spiders share each of these physical characteristics (six eyes in dyads, dark pattern near the eyes, uniformly colored abdomen with fine hairs, no spines on the legs); however, no nonrecluse spider has all four characteristics. On this basis, more than 99% of the spiders found by Californians can be identified as something other than a recluse spider. If, however, you do find a recluse spider in California, it will most likely be the native desert recluse, L. deserta. To further identify Loxosceles spiders to species requires a high-power microscope and the skills of a spider expert (arachnologist).

Brown Recluse Garden Spiders 4…