Unidentified Species of Wolf Spider
Temple, Texas 12-23-03

by Jerry Cates

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Wolf Spiders are common ground spiders that patrol our lawns day and night, reducing the insect population there in ways no pest management regimen could ever hope to match. They scurry across the ground, often venture into homes (especially while the lawn is being mowed; this annoying artifact of lawn-mowing can be reduced, and even eliminated, by mowing the lawn outward from the home, beginning first at the home's perimeter, and working outward for at least fifteen feet, before mowing the rest of the lawn), and are essentially harmless.  Though they will bite if handled, their venom is not considered dangerous. As with all spider bites, secondary infections are possible, and sometimes--though only rarely--medical intervention may be required. Between 2,000 and 3,000 species of Wolf Spiders are known, and 200 or more are known to live in the United States. They have long legs, with the fourth pair being the longest. Spines on the legs are prominent and often, as in this specimen, darker than the leg shaft. 

To get an idea of how many wolf spiders your lawn has on patrol, wait until dark, then go out on the back porch, with the porch lights off, and place a flashlight next to your temple. Shine the light into the grass, and observe the myriad of tiny diamond-like flashes of light that reflect back to your eyes.  These are, most of the time, the eyes of wolf spiders.  They do their work, for you, relentlessly.

The specimen shown here was captured in Temple, Texas, on 12-23-2003. Its body measured, from head to posterior abdomen, 19 millimeters (0.75 inch). Markings on the carapace of wolf spiders are definitive for many genera, particularly the Trochosa, Pirata, and Trebacosa, each of which exhibits a unique pattern of markings. If, as in this particular case, carapace markings are somewhat nondescript, identification to genera is more complicated.

This specimen exhibits a broad pair of darkened blotches with indistinct borders and, in their posterior regions, show complex, radiating pale markings.  The pair of darkened blotches are separated by a pale, indistinct, medial stripe that narrows toward the anterior, and is punctuated with one small, dark, posterior mark (a mark commonly observed on the carapace of most wolf spiders, but that is normally more distinct than in this specimen; the spot is most obvious on the first photograph shown on this page, above).

The eight eyes of the wolf spider are arranged in three rows:  The two furthest back on the carapace, known as the posterior eye row (PER), are two in number and moderate in size.  Four small eyes positioned in a horizontal row just above the chelicerae (pointed appendages that form the spider's jaws) comprise the anterior eye row (AER), and may be of equal size, or with smaller eyes outside (laterally) with slightly larger eyes medially. Two large eyes between these two rows form the posterior median eye (PME) row. The width of the AER, compared to that of the PME row is definitive. 

In this specimen the AER is clearly less than that of the PME row, which rules out the genus Hogna. The apparent lack of long proximal bristles on tarsus 1 (the most distal segment of the spider's first leg, as shown in the photo above), suggests this is a member of the genus Pardosa, but gross features of the specimen suggest otherwise.  Assuming microscopic examination of this spider's tarsus 1 showed a single, proximate, long bristle (which is not visible in the above photograph, due to the photo's poor quality), this specimen would likely belong to the genus Schizocosa.

The markings on the dorsal abdomen, though definitive for many species of spiders, are not so for the Lycosidae. Though the markings are usually distinct, even for the Lycosidae, they are not for this specimen.  Certain of the Schizocosa have vaguely similar markings on the abdomen dorsum.