Research conducted in the Lower Rio Grande Valley of Texas demonstrated the technical feasibility of natural enemy augmentation as a means to suppress infestations of boll weevil, Anthonomus grandis Boheman. Augmentative releases of the pteromalid parasite Catolaccus grandis (Burks) at relatively high rates during an 8-week release period (2,470 female parasites/ha/wk during 30 April - 29 June 1992) was accompanied by a consistently high rate of parasitism among third-stage host larvae (79.1-84.4%) and pupae (52.5-81.0%). Mortality of this magnitude substantially reduced or eliminated host survivorship to the adult stage during the critical first and second host generations, and was accompanied by a significantly lower incidence of damage to cotton bolls in release sites versus controls at the time releases were terminated (0.2-0.3% damage in release sites; 48.3-90.5% in controls).