The cultures of phosphine-susceptible and resistant
Liposcelis Entomophila(Enderlein) were exposed to fixed phosphine concentrations
for varying exposure periods using a continuous flow application of phosphine mixed with air at 25℃,75%RH.Times to population extinction were 6,4,3,2,2d at 50mL/m 3,100mL/m 3,200mL/m 3,400mL/m 3 and 700mL/m 3 of phosphine respectively,for susceptible QLe-3 strains,and for resistant GLZLe-1 strain,times to population extinction occurred at 13,10,7 and 6d at 100mL/m 3,200mL/m 3,400mL/m 3 and 700mL/m 3 of phosphine respectively.The eggs of both strains were more tolerant to phosphine than adults and nymphs.Phosphine may inhibit development of the eggs during exposure,as evidenced by delayed hatching of the eggs of both strains for 3～6 days.The relationship between phosphine concentration and
time to population extinction could be described by an equation of the form of C nT=K.The equation of GLZLe-1 is C 0.41 TPE=138.55(mg·h/L),and that of QLe-3 is C 0.44 TPE=42.05(mg·h/L)