OXYGEN UPTAKE IN INSECTS WITH CYCLIC CO2RELEASE

Abstract

1. The simultaneous determination of CO₂ production and O₂ uptake in Hadrocarabus problematicus Hrbst. is described. Both CO₂ release and O₂ uptake are cyclic, but there is some interburst O₂ uptake. 2. The diaferometrically recorded O₂ uptake is discussed, and compared with the results as obtained with the Warburg technique. 3. In diapausing pupae of the cecropia silkworm (Hyalophora cecropia) the continuous O₂ uptake forms a larger percentage of the total amount of O₂ consumption than in Hadrocarabus. Still there was found an initial maximum of O₂ uptake of short duration at every CO₂ burst. 4. Some experiments on the CO₂ dissociation curve of haemolymph of pupae of Sphinx ligustri are mentioned. There is evidence that in haemolymph a CO₂-binding principle is present. 5. The interaction of O₂, haemolymph and CO₂, resulting in a certain intertracheal pCO₂ controlling spiracle movement, is discussed. Probably the pO₂ is only indirectly involved in the triggering of spiracle opening.