Effect of organic farming on the ladybird beetle diversity (Coleoptera: Coccinellidae)

Abstract

Coccinellidae perform the function of biological control of pests in nature, they eat aphids and other insects, which is important in organic agriculture. The aim of the work was to establish the distribution and species composition of the family Coccinellidae in the organic agro-landscape. The research was conducted at the Skvyra research station of organic production (Kyiv region, Ukraine). Insects were collected by entomological mowing with a net in four stages of plant development. The organic agro-landscape included crops of buckwheat, oats, soybeans and winter wheat. Data from neighbor conventional soybean and winter wheat ecosystems were used for comparison. The agroecosystems of these crops, which included felds, ecotones ”feld – feld protective forest shelter belt”, feld protective forest shelter belts, were studied. The study identifed 10 species of the family Coccinellidae, the number of species ranged from 1 to 89/100 waves, the largest in the ecosystem of organic winter wheat. H. axiridis belonged to the recedents and was found in fve agroecosystems in the amount of 1-7 individuals / 100 waves. The most common species were C. septempunctata, T. sedecimpunctata and larvae of Coccinellidae, which were eudominant in the organic agro-landscape. Species Vibidia sp. was found only in organic agroecosystems of buckwheat and oats. The variety of ladybugs in organic winter wheat was higher than in conventional. Organic soybeans, in contrast, had less variety of Coccinellidae than conventional soybeans, as confrmed by cluster analysis. Species richness in crop ecosystems ranged from 3 to 8 in different study periods. High correlations of insect numbers were found between felds, ecotones and forest shelter belts, as well as between neighbor ecotones and neighbor forest belts, which indicates the migration of insects between these areas. Thus, the diversity and prevalence of Coccinellidae in the organic agro-landscape, compared to the traditional one, has been established. Key words: ladybugs, organic farming, agrolandscape, agroecosystem, crops, species.