The Spider Assemblage (Arachnida, Aranei) in Agroecosystems of the Kuban Plain: Species Composition, Spatial Distribution, and Seasonal Dynamics

摘要

During two years of observations of winter wheat fields, their margins and areas adjacent to forest shelterbelts, 139 species of spiders from 18 families and 92 genera were found using net-sweeping and pitfall trapping. In the fields proper, 87 species were recorded. The species number and species diversity decreased towards the central areas of the fields. High species diversity was recorded in the field edges but not in their central parts. Spiders of the families Philodromidae, Thomisidae, and Araneidae predominated in the herb-layer; the fractions of these families were greater in the fields than in their margins. Species of the family Salticidae were more numerous in the field edges and margins. Representatives of Lycosidae were the most commonamong epigeic spiders, their fraction reaching 90% in the field center. The dominant forms comprised 10% of the species and 80% of the number of individuals. Agrobionts common to the temperate zone of Europe predominated in the central part of the fields. They colonized the fields rapidly and distributed uniformly over the territory in spring, and then redistributed as the crops grew. The species for which the ecological conditions of the fields were favorable colonized the fields regardless of their size; other species were restricted to the field periphery.