Fig. 9. Dynamics of flight force production and flight-specific CO₂ release at flight initiation (A,B) and flight end (C,D) of Drosophila in which respiratory gas exchange was limited to gas flux through abdominal spiracles. (A) Flight force production and (B) CO₂ release, in a single fly exhibiting nine successive flight sequences (superimposed coloured lines). Note the time course of CO₂ release after flight initiation and during the post-flight respiration period. Time after x-scale break indicates mean time of all nine sequences. (C,D) Dynamics of force production (C) and CO₂ release (D) at flight stop averaged over 65 flight sequences derived from six flies. Mean values are plotted in black; grey area indicates s.d. Flight time was 49.9±65.7s (mean ± s.d.). Arrow indicates a transient steep decrease in respiratory CO₂ release immediately after flight stop.