Management of agroecosystems to enhance natural pest regulation requires an understanding of predator ecology and how predatory insects use the landscape and respond to its structural characteristics. A group of predatory insects, ladybird beetles, were selected to study patterns of habitat utilization in response to vegetation type, management practices, and habitat succession.

This work was conducted at the Long Term Ecological Research (LTER) site at the Kellogg Biological Station (KBS. First, a life systems study of Coleomegilla maculata lengi was conducted to determine beetle aggregation sites in the landscape, and to determine paths of energy flow in a beetle-crop system by using stable isotopes. Secondly, abundance patterns of fourteen species of coccinellids were monitored during the growing season using yellow-sticky traps.

The sampled landscape consisted of an array of field crops under different management practices, interspersed with poplar and early successional vegetation. Seven years of information were analyzed using Shannon-Wiener and richness indices, Kendall''s coefficient of concordance, and principal component analysis. The results of the analysis were used to produce a spatially explicit population model.

The main finding of the study were: (a) Ladybird beetle species diversity peaked during the second year of secondary succession with a successive decrease in diversity thereafter. In poplar, there was a "succession" of dominance by three beetle species; (b) Reduced chemical inputs (herbicides and fertilizers) decreased beetle abundance and species diversity in corn fields but these components increased in wheat. In the corn-soybean rotation sequence, C. m. lengi, was most abundant when corn vegetation was present; and (c) Adults of C. m. lengi used woodlots, hedgerows, and rows of trees to aggregate prior to the onset of winter. Large aggregations occurred near agricultural fields where corn or alfalfa was grown the previous summer.