A series of reduced pressure fumigation tests using 60 mm mercury and adult rice weevil insects (as well as some insects more resistant to the fumigant CH₃Br) indicated that the time required for a satisfactory fumigation can be shortened by a factor of 1/24 ~ 1/12 compared with that of normal pressure fumigation and a factor of R5 ~ 1/2 compared with that of conventional reduced pressure fumigation at 260 mm mercury. The authors suggest that 16 ~ 20 g/m₃ of the fumigant CH₃C1 is sufficient but recommended the use of twice that amount for total control.