Nutrition of Entomophagous Insects and Other Arthropods

High efficiencies of food utilization have often been predicted for parasitoids. The larval stages that consume food of high nutritional content are relatively inactive within the host and have a limited food supply, both of which may contribute to the selection for efficient food utilization. Non-nutritional factors are intimately and intrinsically involved in food acceptance and intake. These include physical properties such as form and texture, but also non-nutritive chemicals that elicit specific behavioral and/or physiological responses essential for finding and accepting foodstuffs, and in some cases for initiating behaviors associated with the feeding process itself. In addition to feeding on plants and plant products, many parasitoids, particularily idiobiontic species, feed on potential hosts. Host feeding by koinobiontic parasitoids is less common. Adult female hymenopterans puncture or damage host larvae or pupae and feed on the hemolymph and/or internal tissues. Parasitic hymenopterans are often categorized as proovigenic or synovigenic. Females of proovigenic species complete oogenesis prior to, or shortly after, emergence and lay eggs over a relatively short period of time primarily on larval stages of their host. Host feeding is only important for ensuring that the female lives long enough to deposit all her eggs.