Comparative prey suitability of Ostrinia nubilalis eggs and Acyrthosiphon pisum for Coleomegilla maculata

The effects of Ostrinia nubilalis (Hubner) (Lepidoptera: Pyralidae) eggs and Acyrthosiphon pisum (Harris) (Homoptera: Aphididae), when provided as single prey species and in combination, on life history characteristics of Coleomegilla maculata DeGeer (Coleoptera: Coccinellidae) larvae and adults were quantified. Preimaginal development was not influenced by the larval prey regime; development at 26 ± 1°C was completed in approximately 13.5 days on O. nubilalis eggs, A. pisum, or A. pisum alternated daily with O. nubilalis eggs. The resulting adults weighed 13.0, 10.7, and 12.5 mg when reared on O. nubilalis eggs, A. pisum, and A. pisum alternated daily with O. nubilalis eggs, respectively. Eighteen percent of the individuals died when reared on A. pisum, 28% died when reared on O. nubilalis eggs, and 22% died when fed A. pisum alternated daily with O. nubilalis eggs. Seven adult diet combinations, based on diet regimes of larvae and adults, did not cause significant differences in preoviposition period, interoviposition period, and the number of days on which eggs were laid. Total fecundity was influenced both by larval and adult diet. The diet that resulted in highly fecund females was A. pisum alternated daily with O. nubilalis eggs for larvae and O. nubilalis eggs for adults. Female C. maculata fed O. nubilalis eggs had the highest intrinsic rate of increase and net reproductive rate.