Technical Abstract: Coupled gas chromatography and electroantennogram detection (GC-EAD) analyses of headspace volatiles from apple host tissues revealed a total of 16 antennal responses to which female dogwood borer, Synanthedon scitula (Harris), responded. There were no differences in the amplitude of the response of antennae from virgin and mated females, and the amplitude of the response of females to host odors was greater than that of males. Four compounds, including octanal, nonanal, decanal, and methyl salicylate, were identified from all headspace collections from apple trees. Use of the solid-phase microextraction (SPME) technique revealed that a single volatile compound, a-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 response to injury. An additional compound, methyl-2,4-decadienoate, present only in headspace collections from burr knots infested with dogwood borer larvae on ‘Granny Smith’ trees elicited a strong female antennal response.