The sterol requirements of the larva of the beetle, Dermestes vulpinus Fabr

Abstract

On a diet consisting of 1.5 g. dried debittered brewer''s yeast, 1.5 g. fructose, 0.4 ml. water and 0.03 g. McCollum''s salt mixture (not essential), no growth of the larva takes place unless one of the following sterols is added: purified cholesterol, cholesteryl acetate, 7-dehydrocholesterol and 7-dehydrocholesteryl monobenzoate. Sitosterol, ergosterol, zymosterol, cholestanol, cholestene, 7-ketocholesteryl acetate, 7-hydroxycholesterol, 7-hydroxy-cholesteryl dibenzoate and calciferol (Vit. D2) are inactive. The minimum quantity of sterol required for successful growth is about 1 mg. in 3 g. of food for cholesterol and 7-dehydrocholesteryl monobenzoate, and less than 0.5 mg. in 3 g. of food for 7-dehydrocholesterol.