Instantaneous Measurements of Oxygen Consumption during Pre-flight Warm-up and Post-flight Cooling in Sphingid and Saturniid Moths

A method for instantaneous measurement of oxygen consumption in an open flow respirometry system is described. During pre-flight warm-up in both sphingids and saturniids, oxygen consumption reaches levels 20 to 70 times resting values. J^o, required to maintain the thorax at flight temperature by intermittent wing-quivering and fluttering is about onethird the maximum Vo% during warm-up. The Q10 of resting J^o, averages 2-4 in both sphingids and saturniids. At any given thoracic temperature, l?Ot during post flight-cooling exceeds Po, at rest. Factorial scope (maximum J^orr-resting Ĵ Ot) during warm-up is independent of mass and thoracic temperature. In sphingids it averages 39, in saturniids, 43. Absolute metabolic scope in both groups increases with thoracic temperature and is roughly proportional to VQX. In saturniids about 49 % of the heat produced during warm-up is stored in the thorax; in sphingids the figure is about 73%. The data on metabolic scope, power requirements for flight, Ql0 and body mass are used to develop equations that predict thoracic temperature during flight for both sphingids and saturniids.