Reproductive Response of Coleomegilla maculata (Coleoptera: Coccinellidae) to Colorado Potato Beetle (Coleoptera: Chrysomelidae) Eggs

A laboratory study was conducted to quantify the preoviposition period, duration and frequency of oviposition, and the fecundity of Coleomegilla maculata DeGeer feeding on a range of Colorado potato beetle, Leptinotarsa decemlineata (Say), egg densities. L. decemlineata eggs are suitable prey for C. maculata egg production. A water and honey-Wheast mixture diet was not sufficient for C. maculata reproduction, but 28-48% of adults remained alive on this diet for up to 98d. The preoviposition period was significantly shorter for C. maculata females feeding on pea aphids, Acyrthosiphon pisum (Harris), (5.8-6.8 d) than for females feeding on L. decemlineata eggs (11.3-23 d). At the lowest L. decemlineata egg density (2 eggs per day), females had significantly longer preoviposition periods than at the higher prey densities (5. 10, and >15 eggs per day). Interoviposition periods and the numbers of days on which females laid eggs were not different among diets. Fecundity among females feeding on the different diets averaged from 33.2 to 102.7 eggs and was not significantly different on the preimaginal diet of either A. pisum or L. decemlineata eggs. Results of this study indicate that C. maculata could reproduce and maintain its populations in potato fields when L. decemlineata eggs are scarce.