Osajin and pomiferin, two isoflavones purified from Osage orange fruits, tested for repellency to the maize weevil (Coleoptera : Curculionidae)

The fruit of the osage orange tree, Maclura pomifera (Raf.) Schneid (Morace ae), has long been thought to be repellent to insects. A preliminary study reported here confirmed repellency of fruit extracts to the maize weevil, S itophilus zeamais Motschulsky. Two isoflavones, osajin and pomiferin, were isolated from the mature fruit of M. pomifera in high purity (greater than or equal to 95%). Testing of purified osajin and pomiferin failed to show r epellency. Repellency is likely caused by factors other than isoflavones in the fruit.