Synergistic effect of carbon monoxide mixed with carbon dioxide in air on mortality of stored-grain insects
Feng Wang
Thesis, Master of Science (Biosystems Engineering), University of Manitoba. 72 pages. 2008.
2008
บทคัดย่อ
Rusty grain beetle, Cryptolestes ferrugineus (Stephens), red flour beetle, Tribolium castaneum (Herbst), and granary weevil, Sitophilus granarius (L.), are dominant stored-grain pest species in Canada. A study to determine the effect of carbon monoxide (CO) mixed with carbon dioxide (CO2 ) in air on controlling stored-grain insects was conducted in the laboratory. Within modified airtight gas exposure systems, mixed-age adults of rusty grain beetle, red flour beetle, and granary weevil in tough wheat with moisture content of 15% were exposed for 48, 96, 144 and 192 h to three types of gas mixtures in air, 5% CO, 30% CO 2 , and 5% CO +30% CO2 at 20°C and 30°C, the balance of the gases being air.
Carbon monoxide alone had no effect on mortality of the three insect adults. For C. ferrugineus, there was no difference in mortality between by CO2 alone and CO2 + CO mixture at either temperature for all exposures. However, both T. castaneum and S. granarius had higher mortality in the CO2 + CO mixture than the CO2 alone at both temperatures. Moreover, S. granarius was more susceptible to CO2 + CO mixture than T. castaneum. These results suggest that for certain species CO could be used to increase the efficiency of CO2 , especially at high temperature. Inhibition by CO to electron transport chain at the cellular level is presumed to exert synergistic influence on inducing greater mortality of some insects under CO2 stress.