NUTRITION DES LARVES DE TRIBOLIUM CONFUSUM DUVAL: I. RECHERCHE D'UN RÉGIME SYNTHÉTIQUE BASAL SATISFAISANT LEURS BESOINS NUTRITIFS

Abstract

A purified diet suitable for the study of the qualitative amino acids requirements of the larvae of the Coleoptera Tribolium confusum is presented. The composition of the diet is as follows: amino acid mixture 20%, cornstarch 75.5%, cholesterol 1%, wheat germ oil 1.5%, salt mixture No. 2 U.S.P. XII 2%, yeast 0.5%, vitamin mixture M.V.–II. In presence of amino acids, glucose cannot be used as a source of hydrocarbon. The mixture is very hygroscopic, develops a brown color, and is apparently toxic to the larvae. The importance of choline as a growth factor is demonstrated. Wilson's Liver Fraction L or Liver Concentrate 1: 20 cannot replace this vitamin. Yeast appears to contain unknown factors for it improves growth when added to a diet already supplemented with vitamins known to be essential for the larvae. A mixture of 19 crystalline amino acids known to occur in casein satisfies the nitrogen requirements of the larvae of T. confusum equally as well as purified casein.