Wolf Spider
Harker Heights, Texas 04-19-07

Photographs by Bryan H.

Bryan, a soldier at Fort Hood, Texas, is also a proficient nature photographer.  He supplied me with photos of a wolf spider on April 15, and again, on April 19, 2007.  The photos of the new wolf spider are especially striking in their detail.

Wolf spiders (of the family Lycosidae) are not unique in terms of their gross anatomical features. Several families of spiders fit the general profile, at least from a distance.  The Pisauridae family, or nursery-web spiders, are so similar that only a careful examination of the eyes sets them apart.  Pisaurid eyes are positioned like those of the Lycosids, but (1) each eye is about the same diameter [unlike the present specimen], (2) the anterior row (AER) is curved upward [somewhat like the present specimen, but with a more dramatic curvature], and (3) the four eyes in the posterior row are close enough together to appear to form a single row [quite unlike the pesent specimen].

In the case of the Lycosid, (a) the PME (the two eyes in the second row) are dramatically larger than the rest [clearly the case with the present specimen], (b) the anterior row is either not curved, or, as with the present specimen, is only slightly so, and (c) the distance from each PME and PLE is such that the PME appear to form a median row, while the PLE form a third row. Since for this specimen the PME are quite large compared to the AER, the AER form a gently procurved (upward in the center) row, and the PME and PLE are spaced far apart, this is not a Pisaurid.

We can assume, with some confidence, that the present specimen is a Lycosid. Identifying its species is the next step. Within the Lycosidae 13 separate genera have been recognized.  Markings on the carapace are definitive for many genera, particularly the Trochosa, Pirata, and Trebacosa, each of which exhibits a unique pattern of markings. In this specimen, however, the carapace markings exhibit a simple medial stripe flanked by large, dark blotches that are absent any of the streaks definitive for the Trochosa, Pirata, and Trebacosa, ruling out those genera.

The genera Sosippus, Pirata, and Tarentula can also be ruled out due to location, as none of their species range into Texas, or at least into the region around Harker Heights. The genus Geolycosa, the burrowing wolf spiders, cannot be ruled out, as G. missouriensis, and Arctosa littoralis extend their range into Texas. The genus Pardosa (Thin-legged Wolf Spiders) cannot be ruled out because the tibia and patella of the hindmost leg (leg IV) together may be longer than the carapace, which is a distinguishing feature of this genus. Pardosa lapidicina is found in Texas, has markings similar to those of this specimen, and often has yellow spots on the abdomen (the presence of white spots can be seen on this specimen, but no trace of yellow is noted). The genus Schizocosa cannot be ruled out without examining for conspicuous brushes on the anterior legs, characteristic of the genus.  Finally, the genus Lycosa cannot be dismissed, as many of its numerous species are found in Texas, and many exhibit the gross features shown here. 

I enjoy a challenge... Getting to the bottom of this spider's identification will be serious fun. Analysis of additional anatomical features of this specimen continues...

Many thanks to Bryan and his fellow soldiers at Fort Hood for their service to our country.