The effect of integrated pest management practices in an apple orchard on Heteroptera community structure and population dynamics

The community structure and population dynamics of Heteroptera was studied in an apple orchard in the Czech Republic, between 1992 and 1995. The study investigated the changes which occurred after introduction of integrated p est management (IPM) practices into an intensive apple orchard. The IPM con sisted of establishing grass ground cover or planting six selected herb spe cies in two wide belts along the rows of trees. The IPM areas were compared with areas where chemical control was continued. Seventy Heteroptera speci es were captured (22 predatory and 48 phytophagous). The diversity of heter opteran communities was always higher on IPM plots and six predatory specie s and 24 phytophagous species were only captured on the IPM plots. Annual v ariation of abundance of predatory species on IPM plots was smaller than in phytophagous species. Orius spp. were abundant on the chemical control are as due to abundant Tetranychus urticae C.L. Koch populations, which were pr obably a consequence of the application of pyrethroid insecticides. Other p redatory species were more abundant in IPM areas due to higher prey availab ility. The abundance of phytophagous species was favoured by the herbaceous undergrowth of the IPM plots. The number of predatory Heteroptera species increased after the introduction of IPM practices. Vegetation cover diversi ty is enhanced due to cultivation of the plots with IPM regime and has not resulted in any additional increase in the abundance of predatory Heteropte ra species.