Extracts from white, living, intact females of Heterodera schachtii were prepared with either n-hexane, ethyl acetate, methylene chloride, methanol, or water. All extracts showed sex pheromone activity for males in a biotest system. Enzymes acting on peptides did not diminish male attraction to aqueous extracts from females, and vanillic acid, a substance with sex pheromone activity for males of H. glycines, did not attract H. schachtii males. Aqueous extracts from female gelatinous matrices showed attractivity for males.