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 Coleomeg illa maculata DeGeer feeding on a range of Colorado potato beetle, Lep tinotarsa 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 98 d. The preovipo sition period was significantly shorter for C. maculata females feedin g on pea aphids, Acyrthosiphon pisum (Harris), (5.8-6.8 d) than for fe males feeding on L. decemlineata eggs (11.3-23 d). At the lowest L. de cemlineata egg density (2 eggs per day),females had significantly long er preoviposition periods than at the higher prey densities (5, 10, an d >15 eggs per day). Interoviposition periods and the numbers of days on which females laid eggs were not different among diets. Fecundity a mong 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 indicat e that C. maculata could reproduce and maintain its populations in pot ato fields when L. decemlineata eggs are scarce.