Spatial distribution of hortobiont insects in agroecosystems of Moscow region

The investigations (three years) were carried out in agroecosystems (maize, vetch-oat mixture, and winter wheat), including their adjoining grassy margins. Insects were collected regularly during growing periods by standard entomological sweeping in different zones of agrosystems: in the center (about 150 m from field margins), along perimeter of field-at field edges (7-12 m deep into fields) and at margins. The composition of mass species in the grass layer, except for some phytophagous insects, was similar on the same crops from year to year. Three types of spatial distribution of insects in the agrosystems studied were distinguished: the preference of field (obligate agrobionts), the preference of field margins (some facultative agrobionts, which are able to colonize fields), and relatively even distribution within all zones of agrosystems (eurybionts). The habitat preference in many objects altered during a season and might depend on the kind of crops (for instance, winter or spring cultures). During a season, most of the insects migrated from field margins to field edges and then to the center. Some coincidence of allocation patterns in phytophagous and entomophagous insects were observed.