OBSERVATIONS ON THE RESPIRATORY ENZYMES OF VARIOUS LIFE-STAGES OF CHIRONOMUS PLUMOSUS, CHIRONOMUS STAEGERI, AND AEDES AEGYPTI

¹ Department of Zoology, University of Wisconsin, Madison 6, Wisconsin

1. Larvae of Chironomus plumosus and Chironomus staegeri have an active glycolytic enzyme system.

2. The succinoxidase and cytochrome oxidase systems of C. plumosus, C. staegeri, and Aedes aegypti are least active in the larval stage, more active in the pupal stage and most active in the adult stage. The increase in activity from larval to pupal stage is greater in those species, C. plumosus and C. staegeri, in which the larva, but not the pupa, is resistant to anoxia than in A. aegypti, in which neither is resistant.

3. Male pupae and adults of C. plumosus have a higher rate of succinoxidase activity than females. No sexual difference was found between the cytochrome oxidase activities of pupae or between the succinoxidase activities of A. aegypti adults.

4. The developing eggs of C. plumosus exert an inhibitory effect on the succinoxidase system of the insect and of rat liver.