Three oil diluents were evaluated in application tests against the boll weevil in the laboratory and field at the USDA-ARS Research Laboratory at Stoneville, MS during 1997. The diluents used in these tests were: once-refined cottonseed oil (Yazoo Valley Oil Mill, Greenwood, MS), Orchex ^® 796 and WS2908B (Exxon Research and Engineering Co., Baytown, TX).