Protein Nutrition Of: Tenebrio molitor L. XVI. – Effects of dietary protein concentration on larvae of race F. (1)

The optimal concentration of dietary protein for larvae of Tenebvio molitor, race F, Gembloux strain, has been the subject of various investigations. When casein provided the protein in the diet, the optimal level was between 2 or 3 and 20 % in one case (LECLERCQ & LOPEZ-FRANCOS, 1964) and 20 % in another (DAVIS, 1970). The difference in concentrations apparently was linked to the amino acid compositions of the caseins used in these investigations. When six oilseed meals provided the dietary protein for larvae of T. molitor, better growth was obtained with 10 % than with 3 % of dietary protein (DAVIS & SOSULSKI, 1972). Because comparative nutrition investigations are in progress using larvae of T. molitor and mice or rats, the question of optimal protein concentration in larval diets has again been posed. The mammalian diets regularly contain 10 % of protein; however, this amount of protein cannot be chosen arbitrarily as optimal for larvae of T. molitor. The present paper reports the effect on growth of larvae of T. molitor of graded concentrations of dietary protein from 1 to 32 %, provided by autoclaved protein isolate of soybean.