Alluring response of the parasitoid Phanerotoma hendecasiella Cam to synomones from Hendecasis duplifascialis Hampson-infested jasmine (Jasminum sambac L.) buds and compound identification by GC-MS

The jasmine budworm, Hendecasis duplifascialis, is a serious pest of jasmine that poses a severe threat, as it damages the economic part, the buds. The parasitoid, Phanerotoma hendecasiella is specific to the pest and was reported to be a potent candidate in checking the pest menace naturally. Synomones produced by plants have significance in eliciting host-seeking response in several natural enemies. With the intention to test the oriental response of P. hendecasiella on the saturated hydrocarbons from jasmine buds infested with jasmine bud worm, a laboratory study was conducted using an eight-arm olfactometer. The investigated components were the bud and leaf extracts of the jasmine major pests viz. budworm, blossom midge, leaf webworm and two spotted mites, along with healthy jasmine bud and leaf extracts as standard checks, hexane and water as negative and positive control. The eight arms of the olfactometer were placed with the extracts in filter paper strips. The results revealed that out of the 50 parasitoids released, 11 and 25 oriented to budworm infested bud extracts after 2 and 4 hours of treatment, while it was only one in both controls. Further, GC-MS analysis of the bud worm infested jasmine buds revealed the presence of several compounds with the ability to lure beneficial insects such as allyl iso-thiocyanate, linalool, methyl salicylate and naphthalene. The orientation of P. hendecasiella in budworm infested bud extracts and the existence of potent components in them flags a positive signal for the utility of the parasitoid in natural budworm suppression.