Navarro, S., Agricultural Research Organization, The Institute for Technology and Storage of Agricultural Products, Stored Products Research Laboratory, Jaffa, Israel
Calderon, M., Agricultural Research Organization, The Institute for Technology and Storage of Agricultural Products, Stored Products Research Laboratory, Jaffa, Israel

The effects on mortality and loss in weight caused by 21, 51 and 88% carbon dioxide in combination with relative humidities of 20-22, 54-55, and 95-96% were tested on 0-24 hr old Ephestia cautella pupae, at 26°C. Exposure times ranged from 1 to 6 days. At 54-55%, and 20-22% r.h. pupal mortality was high for all carbon dioxide concentrations used, while at 95% r.h. total mortality was obtained only at the highest carbon dioxide concentration tested. At carbon dioxide concentrations of 51 and 88% a 9-11% concentration of oxygen was present. At 20-22% and 54-55% r.h. loss in weight of pupae exposed to carbon dioxide concentrations of 21% and higher was very pronounced. At 95-96% r.h., none of the treatments resulted in loss in weight exceeding 16% after six days of exposure. A 95% mortality curve represents the interrelated effect of carbon dioxide and relative humidity on the moth pupae. The fumigant effect of carbon dioxide is discussed. © 1974.