Natural Attractants in Colocasia escullenta Blossom for the Oriental Fruit Fly, Dacus dorsalis Hendel

Abstract

A study of potential natural attractants in Colocasia esculenta blossoms for the Oriental Fruit Fly (Dacus doralis Hendedl) was undertaken in the Department of Agriculture, Bangkok, in 1985. Fresh flowers in full bloom and full fragrance were collected in teh morning during the period of June to August to test their attractancy with the flies using an Oifactometer. The results showed the blossoms to be highly attractive to the flies. The attractant was demonstrated to be located in teh spadix and bract. In order to establish the identity of the active compounds, the flowers were extracted, separated, fractionated and purified by silica gel column chromatography eluted by hexane/ether; chemical analysis was undertaken by the GLC & GC-MS methods and the crude extract tested with the flies again. Methyl eugenol, eugenol, methyl ester of fatty acid and high molecular weight alcohol were found in teh active fractions in teh attractant.