Coleomegilla maculata (DeGeer) (Coleoptera: Coccinellidae) is a polyphagous predator that can develop and reproduce on a diet of corn pollen. Effect of corn pollen on C. maculata densities, predation on pest eggs, and egg cannibalism were examined over two years. Before and after anthesis, C. maculata density, pest predation, and egg cannibalism were not significantly different between pollen and no-pollen plots. During anthesis, C. maculata egg and larval densities were significantly higher in pollen than in no-pollen plots in one of two years, whereas predation on pest eggs was significantly lower in pollen than in no-pollen plots in one of two years. Egg cannibalism during anthesis was lower in pollen compared with no-pollen plots in both years.

Egg cannibalism by C. maculata on corn is common but less so when oviposition occurs on the weed hophornbeam copperleaf (Acalypha ostryaefolia Riddell (Euphorbiaceae)). Effect of hophornbeam copperleaf on C. maculata density and egg cannibalism in corn plots were examined over three years, whereas predation on pest eggs was examined during two of the three years. Coleomegilla maculata egg and larval densities were significantly higher in weedy plots during all three years. Pupal density was significantly higher in weedy plots during two of three years, whereas adult density was significantly higher in weedy plots in one of three years. More C. maculata eggs were on corn in weed-free plots than in weedy plots but the difference was not significant; in weedy plots, most eggs were on the weed. However, more older larvae always were on corn in weedy than in weed-free plots. Predation of pest eggs was significantly higher on corn in weedy than in weed-free plots during both years, whereas cannibalism of C. maculata eggs was significantly higher on corn in weedy plots during one of the three years.