The sweet-potato whitefly, Bemisia tabaci (Gennadius), can be controlled with an experimental material, Naturalis(TM), which contains an entomopathogenic fungus, Beauveria bassiana, ATCC 74040, FCI 7744. The insect oviposits on the underside of cotton leaves where the immatures attach. The fungus is a contact mycoinsecticide, and the method of application affects the control achieved. Mechanical airblast sprayers achieve more whitefly control with Naturalis(TM), than conventional boom sprayers.