Instantaneous Measurements of Oxygen Consumption During Pre-Flight Warm-Up and Post-Flight Cooling in Sphingid and Saturniid Moths

Abstract

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. VOO2 required to maintain the thorax at flight temperature by intermittent wing-quivering and fluttering is about one-third the maximum VOO2 during warm-up. The Q10 of resting VOO2 averages 2·4 in both sphingids and saturniids. At any given thoracic temperature, VOO2 during post flight-cooling exceeds VOO2 at rest. Factorial scope (maximum VOO2÷resting VOO2) 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 VOO2. 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, Q10 and body mass are used to develop equations that predict thoracic temperature during flight for both sphingids and saturniids.