Fig. 9. Effects of intermittent flight activity on CO₂ emission from the anterior spiracles (spiracles I) in a split-chamber experiment. Application of an artificial pressure difference P of approximately 50Pa between the two chambers produced a CO₂ output from the anterior spiracles (SpI) of approximately 2.5µls^-1. During the pauses between flights, CO₂ output rises to approximately 3.5µls^-1; it then decreases again during the flight phases (stippled) with a latency of approximately 1s. Sampling rate was 400Hz.