Naturalis-L, a commercial formulation of Beauveria bassiana, was compared to a standard insecticide program for control of the cotton fleahopper in the central Blacklands of Texas. In 1992, densities of fleahopper nymphs were higher in the Naturalis-L treatment when compared to a standard program using Bidrin. Fleahopper infestations were very high in 1993 in the test field and Naturalis-L did not maintain densities below treatment thresholds. Densities of predatory insects, primarily the insidious flower bug, were greater in plots receiving multiple applications of Naturalis-L than in plots receiving the standard insecticides dicrotophos or oxamyl.