THE SENSITIVITY OF DEVELOPING HABROBRACON TO OXYGEN

Abstract

1. Groups of Habrobracon were exposed during post-embryonic development to air, nitrogen, oxygen and carbon dioxide and studied with regard to development and oxygen uptake. Deleterious effects from oxygen and from carbon dioxide were observed after exposure at the white pupal stage, but not after exposure at the larva-in-cocoon stage. No deleterious effects from exposure to nitrogen were found.2. Exposure of white pupae to one atmosphere of oxygen or carbon dioxide caused cessation of development at the pigmented pupal stage in a high proportion of the individuals. The incidence of emergence from cocoons as adults was higher for males than for females. Adults with wing and antennal abnormalities occurred. Exposure to two atmospheres of oxygen or carbon dioxide resulted in greater deleterious effects on development than did exposure to one atmosphere.3. The oxygen uptake of unpigmented pupae exposed to two atmospheres of oxygen is markedly reduced. No such reduction was observed following treatment with two atmospheres of nitrogen or carbon dioxide or one atmosphere of oxygen.