The fuel for sustained mosquito flight

Abstract

Males and females of Aedes sollicitans and Aedes taeniorhynchus were flown on a flight mill and analysed for duration and distance of flight, and for utilization of triglycerides, glycogen, and trehalose. Unfed, blood-fed, and glucose-fed mosquitoes were flown either to exhaustion or for 1 hr. Triglycerides and other lipids were not used for flight. Utilization of carbohydrate was 0·08 to 0·10 cal/1000 m or 27 to 37 cal/hr per g, whether calculated from the utilization of glycogen (in unfed and blood-fed mosquitoes) or from the production of carbon dioxide (in glucose-U- 14C fed mosquitoes). The maximum metabolic rate during flight was four to five times that of non-fed controls. In sugar-fed mosquitoes, glycogen and triglycerides accumulated during flight. Glycogen was not utilized as a flight substrate as long as sugar was available. Starved mosquitoes and mosquitoes flown to exhaustion could resume vigorous flight immediately after a sugar meal. Trehalose did not change during vigorous flight and made a negligible contribution to exhaustive flight. In unfed mosquitoes, the flight following a rest period after exhaustion was sustained by residual glycogen; no increase in glycogen took place while resting. The significance of these results to migration and dispersal in mosquitoes is discussed.