ABSTRACT
This chapter summarizes the information available for the oxygen consumption (V02) of insects during free controlled flight and to examine how flight cost varies with size within and between taxa. It focuses on studies which also report data for morphology, wing stroke frequency, and/or muscle potentials along with V02. During preflight warm-up of asynchronous fliers, the major changes in V02 of the flight muscles correlate with the marked increase in frequency of muscle contraction as thoracic temperature increases. A similar budget for gypsy moths during free flight agrees with measured rates of V02 if heat loss to the head is taken into account. Timothy M. Casey has calculated mechanical power outputs based on morphology and aerodynamic theory and obtained values similar to estimates based on V02 for sphinx moths ranging in size from a few hundred milligrams to 5 g.
