AbstractPlants of three hard red winter wheat varieties differing in their resistance to attack by hessian fly (Mayetiola destructor Say) were compared at the fourth leaf stage for their content of constituents extractable by 80% ethanol. Eleven amino‐acids, five organic acids and two inorganic acids were identified. Seven sugars were separated, two of which were unidentified polysaccharides. The main difference was that the susceptible variety (Tenmarq) contained allulose, or allulose in combination with some other component. This compound was present to a lesser extent in the semi‐resistant variety (Ponca) and not present in the plants of the resistant variety (C.I. 12855). Sorbitol also was found in Tenmarq but not in the other varieties.