Discontinuous ventilation in the rhinoceros beetle Oryctes nasicornis. Direct and indirect calorimetry

Discontinuous gas exchange cycles (DGCs) are frequently observed with insects, i.e. oxygen take up and carbon dioxide release occur
interrupted by periods of a few minutes up to many hours.
The paper presents direct and indirect calorimetric experiments on DGCs of the scarabid rhinoceros beetle Oryctes nasicornis.
A direct/indirect calorimetric experiment is presented. Total and specific heat production rates amount to 0.56mWand 0.42mWg–1
in the first period without DGCs and to 0.43 mW (0.32 mW g–1
) in the second phase, resp. The mean DGC amplitude is 0.184 mW
and thus between 33 and 66% of the total turnover.