The paper presents results obtained at recording under conditions of stresses of different character of activities of enzymes (tyrosinase, DOPA-oxidase, acetylcholinesterase) and level of the catecholamine content in tissues of head and fat body of imago and larvae of housefly from lines with different lifespan. A suggestion is put forward about different mechanisms mediating photoperiodic regulation of metabolism in individuals with different intensity of metabolism.