Flight performance and metabolism of the moth Spodoptera frugiperda

Tethered moths were flown continuously for 4 to 7 hr in a sealed flight mill which allowed the trapping of CO 2 and the recording of distance flown. The respiratory rate was approximately 10 cal/km per g or 30 cal/hr per g in flight, and 5 cal/hr per g at rest. In two experiments, the triglyceride content in flown moths had decreased sufficiently to account for the respiratory CO 2. In subsequent experiments with a different strain of the same species, the lipid content did not diminish significantly during flight. During sugar absorption, the respiratory rate at rest was several times higher than in unfed moths. Glycogen and trehalose levels rose sharply during absorption, both at rest and in flight.