Insect Behavior, Resource Exploitation, and Fitness

Abstract

Optimal foraging theory has stimulated many ecologists to take up studies of insect feeding behavior. It is asserted that study of food choice in animals, generally called the theory of optimal diets, is still in its infancy; however, since its inception more than a decade ago, interest in optimal diets has grown at an impressive rate (124). This statement, reflecting a common view among ecologists, deserves careful consideration. The study of food choice did not start with Emlen's (37) note on time, energy, and food resources. The voluminous literature on food selection by insects is the subject of numerous reviews (11 , 25, 78). What Waddington & Holden (124) probably meant is that the earlier studies of food choice mean very little because they lack a central theory that will explain and predict the foraging of animals (94). If the economics of feeding is the major selective factor governing the evolution of feeding behavior, then the theory of optimal diets would be the central concept around which all studies of food choice must be organized. Perhaps the great hopes for optimal foraging theory as a general explana­ tion for feeding biology are now being tempered ( 1 14), but the debates about the theory still make little or no reference to the physiological basis for food recognition, feeding responses, and nutritional value of foods (4, 5, 29, 49,