The effectiveness of CO2 (concentration 15,20,25,30.35.40 and 45% ) controlling stored grain insects at the different temperatures(32,28℃)
.humidities (70.50%RII) was studied. The results showed that CO2 can successfully control the stored grain insects when the concentration was below 60%; when CO2 concentration was 15%, the stored grain insects were controlled significantly, and the motality increased with the time of
exporsure. For the integrated control of the different species and stages the lowest effective concentration should be 45%, with exporsure time>153. 4h. The effect of CO2 related to the temperature and humidity (RH),LT50,LT99.5 of the different species and stages reduced with the temperature increasing or humidity lowering. The tolerence of the different species to
CO2 was that Tribolium conFUSUM>T. castANEUM>Sitophilus eamais>S. oryzae>Rhyzop-
ertha dominica; the tolerance of the different stages was that adult>larva>pupa>egg. The total lowest effective lethal concentration of CO2 for the different species were: CO2 concentration 45%(exporsure time 930. 4h) for Tribolium confusum, 45% (exporsure time 153. 4h) for T. castaneum,40%(251. 9h) for Sitophilua zeamais, 40% (219. 6h) for 5. o-ryzae. 40% (193. 6h) for R. dominica. The low concentration CO2 can inhibet development of the insects, the development was postponed 7-15d.