Type of cereal flours as factors affecting biological and physiological characteristics of Ephestia kuehniella (Lepidoptera: Pyralidae) larvae

The Mediterranean flour moth, Ephestia kuehniella Zeller is one of the conventional hosts for rearing of natural enemies to be used in biological control programs. In this study, the effects of three cereal flours (wheat, corn and barley) on some biological parameters, nutritional responses, as well as proteolytic and amylolytic digestive activities of the fifth instar larvae of E. kuehniella werestudied to determine suitability of the cereals for optimum growth and reproduction of E. kuehniella. The highest rate of larval survival (0.88) and larval growth index (9.77) were obtained in larvae which fed on corn flour. The relative growth rate (9.17 ± 0.33 mg/mg/day) and the efficiency of conversion of ingested food (12.08 ± 1.11%) were the highest rate for fifth instar larvae which fed on corn flour. The highest protein concentration in midgut of larvae (63.77 ± 2.31 mg/ml) and consequentially, proteolytic activity including tryptic (0.0012 ± 0.00 Umg-1) and chymotryptic (0.543 ± 0.001 Umg-1) were observed in larvae that fed on corn flour. According to the results obtained, corn (Var. 704) was the most suitable cereal for laboratory rearing of E. kuehniella, resulting in the highest rate of biological and physiological parameters.