Requirement of the German Cockroach for Choline and Related Compounds.

Abstract
The omission of choline from an otherwise adequate synthetic diet resulted in complete failure of roaches to grow and in death shortly thereafter. For optimal growth and maturation 2000-4000 [mu]g. of choline/g. of diet were found to be needed. Addition of dimethylaminoethanol or aminoethanol to diets lacking choline but containing 30% of casein resulted in little or no growth. The addition of methionine, dimethylaminoethanol and betaine as supplements to a diet low in choline resulted in an increased growth response in the order named. Aminoethanol was inactive. Dietary betaine replaced choline quantitatively for growth and maturation at all levels of intake, and insects fed betaine contained nearly as much choline as those fed a corresponding amt. of choline.