VITAMINS OF THE B-GROUP REQUIRED BY INSECTS

Abstract

SINCE our last communication on this subject¹, we have grown five different insect species, Tribolium confusum, Ptinus tectus, Sitodrepa panicea, Lasioderma serricorne and Silvanus surinamensis, on an artificial diet, consisting of casein 50, glucose 50, cholesterol 1, insoluble part of yeast 5, McCollum's salt mixture 2, water 15, and wheat germ oil 7 mgm./gm. The following vitamins of the B-group were added in pure substance : B₁, riboflavin, nicotinic acid, B₆, pantothenic acid and p-amino-benzoic acid (50 µgm./gm. of the dry diet), choline chloride and i-inositol (500 µgm./gm.). In a number of parallel tests the vitamins were left out one at a time. The results obtained with Ptinus and Lasioderma are given in Figs.1 and 2, and all the results are summarized in the accompanying table.