Pardosa agrestis is a non-web-building spider in the family Lycosidae, commonly known as wolf spiders.
Pardosa agrestis have brown bodies with longitudinal bands. Females are slightly larger ranging from 6–9 mm, while males range from 4.5 to 7 mm. They are hard to distinguish from their related taxonomic species. P. agrestis is the most abundant spider in central European agricultural habitats, preferring to inhabit open spaces. Its lifespan is around 1–2 years and its diet consists mainly of other arthropods, exhibiting non-sexually cannibalistic behavior at times. It has a long copulation duration that averages around two hours. The two mating seasons are June and August, producing 40-60 spiderlings per cocoon. Pardosa agrestis do not spin webs and are not venomous. They will chase after their pray and deliver bites using their chelicerae.
Description
Pardosa agrestis has a dark brown body with longitudinal bands. It is hard to distinguish from its related species. Pardosa agrestis is characterized by the arrangement of its eyes. Its eight eyes are arranged so that there are four eyes in the front row and two eyes in each back row. There are minimal differences in size between sexes, females being slightly larger. Females range from 6–9 mm, while males range from 4.5 to 7 mm. The average female body size is representative of the abundance of resources in its habitat and also is positively correlated with fecundity.
Habitat and distribution
Habitat
Pardosa agrestis prefers open habitats, specifically arable crop fields. Since Pardosa agrestis populates crop fields in high densities, it potentially plays a significant role as a control agent against insects and pests.
Because Pardosa agrestis inhabit agricultural areas, they frequently face decimation, subsequently rebuilding and recolonizing. Following decimation or disturbances, spiders of this species will recolonize in non-arable areas surrounding their original habitat. Therefore, the availability and quality of non-arable land around the spiders’ natural habitat plays a major role in the abundance of Pardosa agrestis in an arable field. Its population density is highest in farming fields that are a short distance away from long, wide, and grassy road-side strips.
Certain slow-maturing members of Pardosa agrestis are vulnerable during the winter months as they have not yet developed techniques and structures necessary to survive the winter. Presence of woody areas around the spiders’ main habitats provide shelter to overwintering spiders, increasing the likelihood of surviving through the winter by providing them with refuge and sufficient prey. Woody areas also provide shelter to females carrying egg sacs, resulting in enhanced offspring survival.
Distribution
Pardosa agrestis is the dominant surface-dwelling spider species in farming grounds in Central Europe and certain areas in North America and Asia.
Diet
Prey variability
The diet of Pardosa agrestis consists exclusively of small arthropods such as diptera and aphids. The prey targeted is almost always smaller than the size of the spider itself. Pardosa agrestis is a generalist predator. It is not specific in the way it selects prey among the arthropods it predates. Its choice of prey heavily depends on the prey's size, frequency of collision, and encounter. This holds for small and medium-sized spiders. However, large spiders can also feed on larger hard-bodied insects. In the earliest stages of their lifecycle, the spiderlings will be protected by reproductive females; however, adult males and virgin females consume spiderlings as a part of their diet from time to time.
Sexual dimorphism of prey capture
Females without egg sacs have been observed to capture prey more than the males. This is attributed to their larger average size and the need to supply sufficient energy. However, egg-carrying females have significantly less prey capturing behavior.