Abstract:The effect of host plant on the potential of Paecilomyces fumosoroseus for controlling Bemisia tabaci were evaluated by comparing the LC50 and LT50 values of B.tabaci on eggplant, cucumber and melon. The results of regression analysis on the accumulative adjusted mortalities of B.tabaci and the different concentrations of P.fumosoroseus showed that LC50 values of B.tabaci were significantly different with the B.tabaci on different host plants from eight to fourteen days after treatments, the least LC50 of B.tabaci on eggplant, cucumber and melon appeared in fourteen days, ten days and twelve days after treatments, respectively. The LT50 values of B.tabaci are significantly different on host plants between cucumber and eggplant, cucumber and melon with the concentration of 1.0×105 and 5.0×105 conidia/mL of P.fumosoroseus, respectively, but there are no significant difference on the concentrations from 5.0×106 to 1.0×108 conidia/mL of P.fumosoroseus.