Biochemical studies on insect haemolymph—I. Variations in reducing power with age and the effect of diet

Abstract

The variation with age of eight reducing values of the haemolymph of Schistocerca gregaria was determined both for locusts reared entirely on grass and for those reared on an artificial diet to which a very small quantity of grass had been added. Random variation in results found in the former group was considerably reduced by the use of artificial diet, although in each case the normal patterns of variation with age were quite clear. Measurements of the specific gravity of the haemolymph of S. gregaria, together with Lee's values for the variation in blood volume with age, and the above reducing values, have enabled a calculation to be made of the variation with age of the total amounts of various reducing materials present in locust haemolymph. In particular, a very considerable increase in the trehalose content and a much smaller increase in glucose were shown to occur during the fifth instar.