Mortality of Sitophilus oryzae in modified atmosphere with elevated levels of CO2

Abstract

The effect of modified atmosphere with elevated levels of CO2 against Sitophilus oryzae was studied by directly exposing the S. oryzae adults to eight concentrations of CO2 viz., 10, 20, 30, 40, 50, 60, 70 and 80 per cent with five exposure periods of 1, 2, 3, 4 and 5 hours to study the adult mortality. The results indicated that 80, 70 and 60 per cent CO2 concentrations caused complete mortality of adults at two, six and seven days after treatment, respectively after exposing to five hours directly. At 40 and 50 per cent CO2 concentrations, though some of the adults survived even after seven days, but they did not lay eggs and thus 40 per cent and above CO2 concentrations were found to be fatal for the development of S. oryzae. And damage of S. oryzae by CO2 was confirmed with scanning electron microscope.