Effect of codling moth management on orchard arthropods

The effect of codling moth Cydia pomonella management on the arthropod community and on the natural enemies of pests was analysed from 2001 to 2003 in both the tree canopy and the grass cover of three experimental apple orchards under different management strategies: supervised control of codling moth based on chemical protection (C); mating disruption against codling moth, including additional pesticides when needed (MD); and microbiological control with granulosis virus in an organic orchard (O). The three management systems differed in terms of biomass and functional organisation of arthropods. Number of individuals tended to be higher in the O orchard, and the complex of beneficial arthropods of this orchard was based on polyphagous predatory arthropods (including earwigs) in both studied habitats. Conversely, parasitoid Hymenoptera constituted the prevailing group in the arboreal habitat of both the C and MD orchards. The highest diversity and evenness indices were unexpectedly measured in the C orchard. The richness of arthropods was the highest in the grass cover of the O orchard. The opposite was found in the tree canopy, the lowest values being measured in the arboreal habitat of this orchard. Depending on the year, the sampling period and the vegetation strata (apple tree canopy or grass cover), diversity and evenness indices measured in the MD orchard were either closer to the O orchard or to the C orchard