RESPONSE OF ALL ASSEMBLAGE OF COCCINELLIDAE (COLEOPTERA) TO A DIVERSEAGRICULTURAL LANDSCAPE

Changes in species assemblages of predatory coccinellids in response t o landscape structure (habitat diversity and patchiness) was studied i n a southern Michigan landscape during 1989-1990. Three sites with dif ferent mosaics of cultivated (alfalfa, corn, wheat) and uncultivated ( deciduous, field succession) habitats were sampled for coccinellid spe cies using yellow sticky traps. The landscape at each site was charact erized using the Berger-Parker index for habitat diversity and a relat ive patchiness index for habitat fragmentation. Relative abundance, sp ecies richness, species dominance, and the Kendall coefficient were us ed to analyze and compare species assemblages among sites. Principal c omponent analysis (PCA) was used to extract factor components per spec ies and site scores, which were compared with landscape indices using the Pearson correlation coefficient. Thirteen species of coccinellids were captured during the 2 yr of weekly sampling. Of these species, Co ccinella septempunctata (L.) was the dominant species in the landscape and was equally abundant in the 3 sites. Coleomegilla maculata lengi Timberlake was more abundant in the site that had a corn habitat, wher eas Cycloneda munda (Say), Chilocorus stigma (Say), and Brachiacantha ursina (F.) were more abundant in the site that had a deciduous habita t. Overall, the site with a deciduous habitat had higher species richn ess. There were significant differences in species composition between the site with a deciduous habitat and the other 2 sites. Differences observed among sites were significantly correlated with the presence o f uncultivated habitats in the landscape.