Effect of casein and zein as additives on some nutritional and immunological indices of Ephestia kuehniella Zeller (Lep: Pyralidae)

The eggs and larvae of the Mediterranean flour moth, Ephestia kuehniella (Zell.), are widely used to rear parasitoids and predators for biological control programs. In this study, nutritional responses and digestive enzymes activities of the fourth instar larvae, as well as some immunological parameters of E. kuehniella, were studied on the diet containing casein and zein proteins under laboratory conditions. The fourth larval instar reared on diet containing casein had the highest relative rate of consumption (5.9 ± 0.2) and relative growth rate (11.3 ± 0.3). The highest and the lowest activity of lipase, tripcine, elastase, carboxypeptidase and aminopeptidase in larvae fed were on casein and zein proteins. In the immunological study, injection of tween and Beauveria bassiana (Balsamo) Vuillemin in larvae treated by casein protein significantly increased the total number of hemocyte and the number of granulocytes and plasmatocytes. This study indicated that the nature of the protein in the diet effects on physiological mechanisms of feeding and affect the immune response.