The importance of folic acid and unidentified members of the vitamin B complex in the nutrition of certain insects

Abstract

Synthetic folic acid (Lederle) is an important growth factor for 6 insect species. In the absence of folic acid, growth is very slow (Tribolium, Ephestia) or ceases entirely (Tenebrio), and the mortality is high (Ephestia, Tenebrio). For Ephestia kuehniella, crystalline vit. Bc has an effect as good as, if not better than, synthetic folic acid. Xanthopterin has a similar effect on Ephestia, but only in quantities approx. 1000 times larger than those used of folic acid. It has no effect on Tenebrio. The minimum optimal requirements for folic acid of the insects investigated are between 0.125 and 0.5 7/g. of dry diet. Tenebrio requires, in addition to folic acid and the other known B vitamins, a factor contained in a charcoal filtrate prepared from liver or yeast extract.