A COMPARATIVE-STUDY ON THE TOXICITY OF CARBON-DIOXIDE TO THE DEVELOPMENTAL STAGES OF CALLOSOBRUCHUS-MACULATUS (FAB) AND CALLOSOBRUCHUS-SUBINNOTATUS (PIC)

Mortality of eggs, larvae, pupae and adults of two bruchids, Callosobr uchus maculatus (Fab.) and C. subinnotatus (Pic.), exposed to an inert atmosphere of 100% carbon dioxide, was observed at a temperature of 3 2 degrees C and a humidity of 70%. There was an observed 100% mortalit y for the eggs and the adults of both species after an exposure period of 24 h. All the young larvae of both species died within an exposure period of 48 h compared to the older larvae which required an exposur e period of 72 h for 100% mortality, The pupal stage was the most tole rant stage to carbon dioxide and exposure periods of five and six days were required to obtain 100% mortality for C. maculatus and C. subinn otatus, respectively.