THE IMPORTANCE OF PREDATORS IN CEREAL CROP AGROBIOCENOSIS IN LESKOVAC

Abstract

The monocultural way of grain crop production may cause the massive emergence and development of both harmful and useful organisms in agrobiocenosis. Predators as natural enemies give a significant contribution to the reduction of pest population. The aim of the research was to monitor the biodiversity of predators and establish the differences in their faunistic composition, with regard to the agrobiocenosis of both spring and winter crops. The following standard entomological methods were used throughout the research: visual inspection, examination of above-ground parts of a plant, the sweep net method and laboratory processing of gathered material. The research was carried out from 2011 to 2013 on the experimental plot of the Agricultural High School in Leskovac. The research shows that the diversity maintenance and natural bioregulatory mechanisms are the basic rule in preservation of the grain agrobiocenosis against harmful insects. The predatory activities towards aphids were registered among the following five species of ladybirds belonging to the family of Coccinellidae: Coccinella septempunctata L., Adalia bipunctata L., Hippodamia variegata Goeze, Propylea quatourdecimpunctata L. and Calvia quatourdecimpunctata L. and 2 predators of family Chrysopidae: Chrysopa perla L. and Chrysopa carnea Steph. The research results showed similarity among ogranisms present in respective agrobiocenoses of spring and winter crops that were compared.