Why are insects so energy-efficient while flying? Is it because
of their light weight and aerodynamics or due to very efficient
biochemical transformations (food->energy)? Insect flight muscle
is capable of achieving the highest metabolic rate of all animal
tissues, and this tissue may be considered an exquisite example
of biochemical adaptation. Locusts, for example, may (almost
instantaneously) increase their oxygen consumption up to 70-fold
when starting to fly. In humans, excercise can increase O2
consumption a maximum of 20-fold, and for birds in flight the
figure is about 10-fold (Wegener, 1996; Sacktor, 1976). As
Wegener (1996) has put it (in his definitive paper): Flight is
powered by ATP hydrolysis, and these impressive metabolic rates
are achieved by very effective control of ATP hydrolysis and
regeneration. Wegener, G. (1996) Flying insects: model systems
exercise physiology Experientia May 15;52(5):404-12. (See here)
Sacktor B. (1976) Biochemical adaptations for flight in the
insect. Biochem Soc S