Pardosa milvina

A common and widespread spider in North America, Pardosa milvina can be found in the United States from New England to Florida and west to the Rocky Mountains. It is most common in the eastern third of Texas between the months of May and September. (Foelix, 1982; Jackman, 1997)

This wolf spider can be found in grasslands, dry open woods and also in wet grounds along streams and ponds. Recently, P. milvina has been found among various agricultural crops. This spider does not create a snare or web. Rather, it is somewhat nomadic, resting under rocks and grass in between hunting. (Jackman, 1997)

Wolf spiders (family Lycosidae), are among the most common spiders worldwide. Their colors range from black to brown or tan with lengthwise dark and light stripes. Their eyes (they have eight) are arranged in three rows of four, two, and two. The anterior eyes (those in the first row) are smallest, and are in a straight line. The middle row has the largest eyes, and the eyes in most posterior row can be nearly as big as those in the middle. All eyes are dark in color.

The genus Pardosa is large, and itan be difficult to differentiate between species in this genus. In fact, only an expert can reliably tell members of the genus from one another. P. milvina does exhibit certain traits that distinguish it from other wolf spiders. The legs are long and thin with extremely long spines. Scopulae are claw tufts on spiders' legs that aid them in gripping during locomotion. This spider does not possess scopulae and therefore cannot climb smooth surfaces. The cephalothorax is highest in the head region, or carapace. Chelicerae are much smaller than in other wolf spiders, measuring 4 to 9.5 mm. The dorsal stripes common to wolf spiders are more wavy than in other species. The abdomen has yellow spots. Sexual dimorphism exists in this species. The males have white hairs on the patella of the legs. These spiders are considered small. The length of females ranges from 5.1 to 6.4 mm and male length ranges from 4.3 to 5.0 mm. (Jackman, 1997; Milne and Milne, 1980)

Pardosa milvina does not build a shelter. It roams freely over stones and among grasses and other low vegetation. This spider has a small territory. Basking in the sun often helps this spider to keep its body temperature high and to be ready for pursuit of prey. Pardosa milvina typically reacts to vibrations from both birds of prey and other predators as well as from possible prey for the spider. Having eight eyes, one might think that visual stimuli heavily affect P. milvina. However, the eyes of this wolf spider only allow it to see coarse objects, the exception being when objects are extremely close.

When two male wolf spiders encounter one another in the presence of a female, they get into threatening stances and sometimes will fight. The attacking male is usually the winner and will appear to flaunt his superiority with jerking movements. A selective advantage is associated with this practice: the winner has better chances of mating with a female. (Foelix, 1982; Milne and Milne, 1980)

Visual and tactile communication occur during courtship. Visual stimuli are important to this species in capturing prey. These spiders respond to vibrations. (Foelix, 1982; Grzimek, 1972; Jackman, 1997; Milne and Milne, 1980)

Like most every spider, P. milvina is carnivorous. Previously thought of as active hunters, this wolf spider appears to obtain food more often as a "sit-and-wait" predator. This makes P. milvina a bit different from most other wolf spiders, which tend to hunt by sight and chase prey. Wolf spiders are so named because of the way in which they pounce on their prey with great speed and strength. The spider then envenoms its prey with fangs, at the same time puncturing the body so it may suck the body fluids. Staying near the ground during the day, large numbers have been found feeding in cotton fields at night. Common food includes the cotton fleahopper, insect eggs, crickets, locusts, ants, grasshoppers, and other spiders. Pardosa milvina eats about 3.5 mg of insects daily, equivalent to 12% of its body weight. (Foelix, 1982; Preston-Mafham and Preston-Mafham, 1996)

This spider is able to bite humans if defending itself. These bites can cause skin irritation or possibly lesions. (Jackman, 1997)

Most believe that P. milvina benefits humans by limiting insect and pest populations. Like most other spiders, P. milvina is a generalist, eating a variety of other animals (mostly other invertebrates). This leads some to believe that this increases the spider's effectiveness as a population limiter. Yet others feel that since the spider does not specialize in any single species and does not live in colonies, it cannot effectively limit the populations of pests. Thus, although P. milvina shows behaviors which are of potential benefit to humans, it is difficult to determine the extent of the actual benefit provided. (Foelix, 1982)

This species is not a special conservation concern.

There are approximately 2,500 species of wolf spiders worldwide. (Foelix, 1982)