Heartbeat and body movement: roles in gas exchange in Galleria mellonella L-(Lepidoptera : Pyralidae) pupae

The objective of the present article is to analyse the role of heartbeat an d body movements in respiratory function in Galleria mellonella L. (Lepidop tera: Pyralidae) pupae with clear gas exchange cycles. We did not find any direct evidence of co-ordination between heartbeat and respiration or body movements and respiration. Cyclic CO2 output was independent of abdominal m ovements and heart pulsations during the entire pupal development. In young pupae, heart activity periods were independent of abdominal movements. In middle-aged pupae, there appeared a clear trend towards the coincidence of heartbeat periods with the periods of abdominal movements. In late pupae, t he heart pulses and the contractions of body skeletal muscles were mostly s ynchronized. II may be suggested that the contractions of intersegmental so matic abdominal muscles support the heartbeat, and, in this way, the hemoly mph flow is accelerated. The heart and circulatory action may facilitate ga seous diffusion in the tracheae. (C) 1999 Elsevier Science Ltd. All rights reserved.