Electrophysiological Response of Female Dogwood Borer (Lepidoptera: Sesiidae) to Volatile Compounds from Apple Trees

Abstract

Coupled gas chromatography and electroantennogram detection (GC-EAD) analyses of headspace volatiles from apple host tissues revealed a total of 16 compounds to which female dogwood borer, Synanthedon scitula (Harris), antennae responded. There were no differences in the amplitude of the response of antennae from virgin and mated females, and no consistent responses to host odors were generated from male antennae. Four compounds, including octanal, nonanal, decanal, and methyl salicylate, were identified from all headspace collections taken from apple trees. Use of the solid-phase microextraction (SPME) technique revealed that a single volatile compound, α-bergamotene, emanating from larval dogwood borer frass elicited a strong female antennal response. This compound was also present in headspace collections from ‘Red Chief Delicious’ apple trees with burr knot tissue infested with dogwood borer larvae and from 1-d-old cut bark on ‘Granny Smith’ trees, suggesting that it is produced by apple trees in resp...