The Consumption and Utilization of Food by Insects

A great deal is known concerning the qualitative nutritional requirements of insects. The quantitative aspects of insect nutrition have, however, received less attention, and there have been few studies on the rates of intake and the efficiency of food utilization. In particular, relatively little is known concerning the intake, digestibility and efficiency of conversion of defined diets. Quantitative work with artificial diets has usually involved only measurements of the amount of a particular nutrient required per unit of diet. Insects as a group feed upon a remarkably diverse list of organic substances. At the same time most species show a high degree of specificity in their choice of food. It seems apparent that adaptive nutritional differences must be sought on a quantitative level and that a meaningful comparative nutrition of insects will not emerge until quantitative studies are emphasized. The determination of absolute requirements for dietary constituents depends upon the measurement of intake. Differences in food efficiency can be demonstrated only by measuring intake and growth. Digestibility should also be measured since it can be expected to vary widely with different foods. The efficiency with which digested food is used for growth will vary not only with the maintenance requirement for energy but also with the balance of nutrients.