The Influence of Aphid Prey Consumption on Searching Behavior, Weight Increase, Developmental Time, and Mortality of Chrysopa Carnea (Neuroptera: Chrysopidae) and Hippodamia Convergens (Coleoptera: Coccinellidae) Larvae

The behavior of larval stages of the green lace wing, Chrysopa carnea Stephens, and of the ladybird beetle Hippodamia convergens G.-M. were studied in the laboratory. With increasing hunger level, only first instar H. convergens larvae spent more time searching in the upper part of alfalfa stems, where both prey aphids, Acyrthosiphon pisum (Harris) and Acyrthosiphon kondoi (Shinji), are found. All larval instars tested except first instar C. carnea visited more stems per unit time with increasing hunger level. The weight gain, the developmental time, and the mortality of all larvae were adversely influenced at low food levels, but differently for each predator size and species. C. carnea larvae had higher rates of fat body utilization and weight gain than coccinellid larvae.