Experiments were conducted to observe the feeding and food selection-behaviour of different instars of the pod-borer Helicoverpa armigera (Hübner) in response to choices between the cultivated and a wild species of Cajanus. First and second instars fed upon a cultivated variety of Cajanus cajan in preference to a wild species, C. scarabaeoides and on flowers of C. cajan, rather than pods or leaves of C. cajan. First and second instars preferred pods of C. scarabaeoides with trichomes removed to pods with trichomes present. All instars fed upon pods of C. cajan rather than those of C. scarabaeoides. Solvent extraction of the pod surfaces affected the feeding of larvae, in some instances. They preferred the unextracted pods of C. cajan; the extracted pod of C. scarabaeoides (first and second instars) or the unextracted pod of C. scarabaeoides (fourth and fifth instars). Glass-fibre disc bioassays showed that the methanol, hexane and water extracts from the pod-surface of C. cajan stimulated the feeding of fifth instars. The experiments have shown that characteristics of C. cajan, such as either the compounds present or the type and distribution of trichomes on the plant surfaces, can determine the susceptibility of C. cajan to pod-borer larvae.

Larvae of Phormia regina (Meigen) (Diptera: Calliphoridae) were reared, in isolation, upon either lamb's liver or meridic diets that varied in protein- and carbohydrate-content. An artificial diet containing 53% protein (by mass of dry ingredients) resulted in the heaviest P. regina pupae and shortest development time when compared with larvae reared upon lamb`s liver and all other diets. In diets where the concentration of protein was less than that of carbohydrate, the level of carbohydrate became important. In a diet containing 22.6% protein it was neither the diet with the highest (51%) nor lowest (17%) concentration of carbohydrate that adversely affected development. Specifically, an intermediate level of carbohydrate (33.9%) resulted in an extended larval period, together with increased mortality and reduced pupal weights. Larvae reared in groups of 10 on either liver or a diet containing 53% protein were heavier than those reared in isolation. Group-rearing hastened development on liver, but not on the meridic diet. The results are discussed in relation to the nutritional ecology of saprophagous calliphorids.