STRUCTURE OF LADYBIRD (COLEOPTERA, COCCINELLIDAE) ASSEMBLAGES IN APPLE - CHANGES THROUGH DEVELOPMENTAL STAGES

Larvae, pupae, and adults of ladybird beetles were observed in an insecticide-free and an insecticide-treated block in an apple orchard near Budapest, Hungary during 1980-1982. Species numbers and densities in all developmental stages were higher and species turnover was lower in the insecticide-free block. Diversity and similarity indices showed more diverse and constant assemblages in the insecticide-free block. The adult assemblage was the most rich in species, with 19 species in the insecticide-free and 12 species in the treated block. The most common species overall were Coccinella septempunctata, Adonia variegata, Adalia bipunctata, and Exochomus quadripustulatus. The larval assemblage included nine and eight species for the untreated and treated blocks respectively, whereas the pupal assemblage had eight species in both blocks. Immature stages of 11 species were found in at least 1 yr and 10 of these was able to complete development in the orchard. The rate of success was higher in the insecticide-free block for most species. Only A. bipunctata reproduced successfully in both blocks in all three years but A. decempunctata and C. septempunctata were often successful.