Protein, lipid and carbohydrate use during metamophosis in the fire ant, Solenopsis xyloni

Abstract. Concentrations of total sugars, lipids and soluble proteins were measured in prepupae and pupae of a native fire ant, Solenopsis xyloni W. M. wheeler (Hymenoptera: Formicidae). Changes in the concentratons of these reserves were examined over the course of metamorphosis, in response to starvation, and in relation to body size. During metamorphosis, only lipid concentrations changed during the prepuapal period, dropping slightly. During the pupal state, however, approximately 75% of total sugars, 45% of lipids and 40% of soluble proteins were used. Starvation immediately prior to metamorphosis greatly decreased the quantity of carbohydrate detected at the beginning of the prepupal stage. Soluble protein levels were also slightly reduced. In contrast, lipid concentrations in prepupae increased in individuals that had been starved for 2–4 days immediately before metamorphosis. The relationship between body size and amount depended on the type of reserve. Lipid concetrations decreased with increasing size, while carbohydrate levels tended to increase slightly. Overall, soluble protein concentration did not change with size. Gel electrophoresis showed that two major polypeptides account for most of the soluble protein and one on these decreased sharply over the pupal period.