Development of Three Populations of Coleomegilla maculata (Coleoptera: Coccinellidae) Feeding on Eggs of Colorado Potato Beetle (Coleoptera: Chrysomelidae)

Laboratory experiments were conducted to compare the preimaginal survival, development rate, adult weight, and sex ratio of 3 Coleomegilla maculata DeGeer populations feeding on Leptinotarsa decemlineata (Say) eggs and pea aphids, Acyrthosiphon pisum (Harris). Preimaginal survival of C. maculata from Iowa, Rhode Island, and Honduras reared on L. decemlineata eggs alone ranged from 1.7 to 30%. The highest mortality of C. maculata immature stages occurred during the early (1st and 2nd) stadia. Higher preimaginal survival for Rhode Island population (30%) than for Iowa (5%) and Honduras (1.7%) populations suggests that C. maculata in Rhode Island may be better adapted to feeding on L. decemlineata eggs as early instars. Development of C. maculata at 26°C was slowest (18 d) on L. decemlineata eggs alone and fastest (13 days) on pea aphids alone. However, when 1st and 2nd instars of C. maculata were provided with aphids. followed by L. decemlineata eggs, there was no observed delay in larval development. Older C. maculata larvae readily feed on L. decemlineata eggs, and in the presence of additional prey such as aphids for early instars, L. decemlineata eggs alone are an adequate diet for subsequent C. maculata development and survival.