Some patterns in distribution of the ground beetles (Coleoptera, Carabidae) at the agrocenoses of Ukraine

Abstract

According to the habitat layers, ground beetles of agrocenoses of Ukraine were divided on three groups: preferential inhabitants of the soil (geobios), inhabitants of the surface of the soil and plant litter (stratobios) and preferential inhabitants of the plants (phytobios). Ground beetles of geobios were represented with about 20 species, from which only five species were relatively numerous. About 370 species were registered in stratobios (about 90 are dominants or subdominants). The inhabitants of the plant layer encompassed about 10 species, but most of them were rare in agrocenoses. Most spring zoophagous species of Carabidae (mainly species of the genus Poecilus) are characterized by a low level of aggregation (Ka = 0.25–0.35). A higher degree of aggregation was recorded for small species of ground beetles (Bembidion, Microlestes) and some mixophagous (Amara similata, A. aenea, Harpalus distinguendus). At summer, the higher level of aggregation was registered (Ka = 0.35–0.46), especially for summer-autumn group of ground beetles (Calathus ambiguus, C. melanocephalus, Harpalus rufipes) and some multi-seasonal species (Pterostichus melanarius). An essential factor affecting the distribution of ground beetles on the field is the density of the plants. On the plots with rare vegetation the accumulation of thermophilous and mesoxerophilous species (Poecilus crenuliger, P. koyi, P. puncticollis) was observed (significant correlation). Higher number of mesophilous and mesohygrophilous Carabidae (Bembidion properans, Poecilus cupreus, P. punctulatus) are registered on the plots with dense vegetation, especially during reproduction period. An increase in the number and diversity of the Carabidae are observed in relatively small fields (up to 50–60 ha), bordered by forest belts or natural biotops. In large fields (more than 100 ha) surrounded by similar crops, the abundance of dominant species of Carabidae was significantly decreased.