Spider identification

Tips for identifying spiders

The key is designed for observing spiders as they might naturally appear. If the spider is preserved in alcohol, it is best to remove it and let it air dry for a few minutes. For some species, the coloration of the body is structural, generated from spectral reflectance of the body parts rather than pigment. Alcohol will affect the ability of structures to reflect light, so preserved specimens may not appear the same color as live spiders. Also, some of the dark spiders (e.g., Zelotes, Nodocion) will appear lighter if they have been sitting in alcohol for extended periods, and they may not darken if allowed to air-dry. Pictures of these spiders in alcohol are also provided.

All pictures of spider genitalia were taken with the body part totally submerged in alcohol. The alcohol dampens the reflectance from the body hairs and allows better visualization of the structures below. At first glance, the pictures of a particular female’s genitalia may not match your specimen. Often there are many setae (i.e., hairs) that curve over the area of interest and obscure the view, such as in wolf spider females (Lycosidae). In order to present the best possible image on the fact sheet, a fine pin (usually an insect pin) may have been rubbed over the area to knock off the setae to allow a clearer view. Doing this with your specimen may facilitate accurate identification.

Forceps with very fine tips are useful for manipulating spiders. It helps to have forceps for each hand in order to move legs out of the line of sight.