MORTALITY OF THE COWPEA STORAGE BRUCHID, CALLOSOBRUCHUS-MACULATUS (FAB) IN SOME HIGH-CARBON DIOXIDE ATMOSPHERES

The mortality of adults, eggs, larvae and pupae of the cowpea storage bruchid, Callosobruchus maculatus (Fab.) was observed in four differen t high carbon dioxide (CO2) in air atmospheres (88% CO2, 70% CO2, 60% CO2 and 50% CO2) at 25-degrees-C and 32-degrees-C respectively, and 70 % RH. All the developmental stages of C. maculatus were completely kil led within 5 days in the 88% CO2. in air atmosphere and within 12 days in the other high CO2 atmospheres tested. The adult and egg stages we re most susceptible, and the old larvae and pupae, the least susceptib le to the high CO2 atmospheres. Mortality of C. maculatus was signific antly influenced by the level of CO2, stage of insect development, exp osure period and temperature.