Abstract: Temperature-dependent development in the Asian corn borer,Ostrinia furnacalis (Guenee) was determined at nine constant temperatures between 10 ℃ and 34 ℃.Except for 10 ℃ development of all life stages occurred at the temperatures tested,however,mortality was significantly great at the extreme temperatures (12 ℃ and 34 ℃).Egg,larvae and pupae duration accounted for 17%,57% and 25% of total one of immature stage,respectively.Lower developmental thresholds estimated to be 10.38,10.06 and 11.07 ℃ for eggs,larvae and pupae,respectively.Upper limited thresholds were 28.00,31.00 and 31.00 ℃ for eggs,larvae and pupae,respectively.The heat-unit requirements for egg stage were 79.15 degree-days,for larval stage were 339.73 degree-days,and for pupal stage were 128.82 degree-days,respectively.Overall,heat-unit requirements for development from egg to adult were 539.91 degree-days between lower developmental threshold 10.35 ℃ and upper limited threshold 32 ℃.