CYCLIC CO2RELEASE IN DIAPAUSING AGAPEMA PUPAE

Abstract

By intubation, normal spiracles were shown to be essential for the occurrence of alternating periods of rapid ("burst") and slow CO2 release, and for water retention, in diapausing pupae of the moth Agapema galbina. Anoxia liberates additional stored CO2 and results in an extra long interburst period, supporting the idea that both O2 and accumulating CO2 act as a spiracular trigger. The interrelations between burst volume, interburst CO2 release rate and cyclic length in individuals, in populations and in pupae exposed to varied ambient pO2 are analyzed statistically and discussed in relation to spiracular behavior and the rationale of the CO2 release cycle.