Development of Coleomegilla maculata on diets of two species of aphid.
The sugarcane aphid, Melanaphis sacchari (Zehntner) (Hemiptera: Aphididae), is an exotic agricultural pest that feeds on sorghum (Sorghum bicolor (L.) Moench) in the United States and Mexico. As with most invasive pests, it was introduced without its natural enemies. Coccinellids, commonly found in agricultural systems, are generalist predators of aphids. The lady beetle Coleomegilla maculata (Degeer) (Coleoptera: Coccinellidae) feeds on M. sacchari and might be a potential agent for biological control in sorghum fields. In this study, we quantified the development and growth of C. maculata on an ad libitum diet of either M. sacchari or pea aphid, Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae). Daily measurements of larvae, developmental time for each life stage, and size (length and width) of adults were recorded. Coleomegilla maculata completed its life cycle on a diet of M. sacchari. However, C. maculata development on a diet of M. sacchari was 12.5% longer than on A. pisum. Coleomegilla maculata also was approximately 10% smaller when fed M. sacchari. Although C. maculata can complete development on a diet of M. sacchari, it might not be the ideal diet for this predatory lady beetle. Further research is needed to evaluate diet preference in the field and effects of diet on reproduction of C. maculata.