Methods of Evaluating the Chemotropic Response of Boll Weevils to Extracts of the Cotton Plant and Various Other Substances1

Abstract

Two methods are described for testing the chemotropic response of the boll weevil, Anthonomus grandis Boheman, to various substances. In one method, solutions of pure chemicals or extracts of the cotton plant were applied to a feeding dish containing diet. In the other, plant parts were placed in a small container covered with a paraffin film to prevent contact of the test material by the insect. The behavior of the boll weevil in both assay methods is described and the applications of the methods are discussed. A solvent extraction of cotton plant parts and the chromatography of the extract are described. By the use of the diet method, several fractions attractive to the boll weevil were found.