Laboratory and field experiments were conducted to assess the effectiveness of insecticidal toxins from Verticillium lecanii (Zimm.) Viégas on Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) in the greenhouse. In the laboratory, crude toxins from three strains of V. lecanii (V3450, Vp28, and Vl6063) at 1000 mg/L were applied systemically to eggplant seedlings that were then exposed to whiteflies. Deterrence of adults and toxicity to offspring were then evaluated. The formulaeIIPCTox=NITrNＩＣk=PhTr•NFTr•SETr•SNTr•SPTrPhCk•NFCk•SECk•SNCk•SPCkwere used to assess the interference of the toxin to the laboratory population of whiteflies. Insecticidal toxins from V. lecanii at 400 mg/L and chemical pesticides diluted 1∶1000 were tested against B. tabaci on eggplants in the greenhouse. Estimated population indices from life tables constructed for the 5th and 6th generation of B. tabaci were respectively 1.88 and 0.68, for V. lecanii toxins and 12.95 and 30.23 for chemical insecticides. The interference indice of population control (IIPC) values were 0.064 and 0.023, and 0.41 and 1.01, respectively. This predicted a decreased 7th generation whitefly population after spraying the crude toxin in contrast to an increase on plants treated with chemical insecticide that surpassed that on untreated plants, this despite a smaller index of the whitefly population immediately after spraying chemical insecticide. These results indicted that application of crude toxins from V. lecanii to be the preferred treatment for control of B. tabaci and conservation of their natural enemies in the greenhouse environment