Abstract
Capacity to adjust to variable resources of food is a useful criterion for assessing the regulatory influence of predators on the population of prey. Anatis mali Auct. was better adapted than Coleomegilla maculata lengi Timberlake to tolerate a shortage of food. When the food supply was increased, survival and adult weight increased in both species – adult weight to a much greater extent in A. mali than in C. maculata, and developmental time decreased in A. mali, but was unchanged in C. maculata. C. maculata was better able to withstand regularly occurring periods of intermittent feeding than a shortage near the end of its development.The conversion ratio of third-instar A. mali larvae and the growth rate of C. maculata larvae were higher when individuals were fed on Acyrthosiphon pisum (Harr.) than on Rhopalosiphum maidis (Fitch). Between the minimum food requirement and the maximum quantity eaten, the conversion ratio of A. mali decreased whereas that of C. maculata remained constant except at the highest quantities of food where the rate of intake increased and the ratio decreased. Relative food intake rate is an accurate criterion for comparing stages and species of predators that are fed on various foods.