THE NUTRITIVE REQUIREMENTS OF TENEBRIO MOLITOR LARVAE

¹ From the Department of Pharmacology, Indiana University School of Medicine, Indianapolis

1. A standard experimental method is presented which can be used to investigate factors that modify the nutritive responses of molitor larvae.

2. Larvae failed to grow when fed a vitamin-free diet of casein, fat, carbohydrate, salt mixture and cholesterol but, when this diet was supplemented with yeast or liver, optimum growth occurred.

3. When the above diet was supplemented, individually, with vitamins A, D, C, E, K, choline, thiamine, riboflavin, pyridoxin, nicotinic acid and pantothenic acid, negative results were obtained. However, when added collectively to the diet, approximately one-third optimum growth resulted.

4. When different combinations of the above vitamins were added to the diet, no appreciable growth occurred unless the diet contained thiamine, riboflavin, pyridoxin, nicotinic acid and pantothenic acid. Conversely, if any of these five factors was omitted, results were essentially negative. Vitamins A, D, C, E, K and choline had no effect.

5. On the assumption that optimum growth on yeast might be caused by phosphorylated flavin, lactoflavin phosphate was investigated. The phosphorylated flavin caused no better growth than synthetic riboflavin, indicating that yeast contains larval growth factors additional to the above vitamins. Biotin, paraminobenzoic acid, folic acid and inositol were not studied.

6. Molitor growth is suggested as a method of biological assay for thiamine, riboflavin, pyridoxin, nicotinic acid and pantothenic acid.