Cherry bark tortrix, Enarmonia formosana: Olfactory recognition of and behavioral deterrence by nonhost angio- and gymnosperm volatiles

We tested the hypothesis that males and females of the cherry bark tortrix (CBT), Enarmonia formosana, antennally perceive and behaviorally respond to volatiles from nonhost plants. Volatiles from flowering cherry trees, Prun us serrulata Kwanzan, and from nonhost trees, including trembling aspen, Po pulus tremuloides, grand fir, Abies grandis, Norway spruce, Picea abies, an d Scots pine, Pinus sylvestris, were captured on Porapak Q and extracts ana lyzed by coupled gas chromatographic-electroantennographic detection (GC-EA D). Compounds that elicited responses from male and female antennae were id entified by coupled CC-mass spectrometry (MS) and by comparative CC-MS and GC-EAD with authentic standards. In field cage and field experiments, nonan al from aspen trees and (+/-)-alpha-pinene from coniferous trees were effec tive in reducing captures of male CBT in pheromone-baited traps and deterri ng oviposition by female CBT on cherry blocks. Recognition of nonhost volat iles, such as nonanal and alpha-pinene, may allow male and/or female CBT to avoid trees that provide inadequate concealment from predators during call ing, resting, and copulation and that are unsuitable for oviposition and de velopment of offspring. Nonhost volatiles may also be exploited for control of CBT by disrupting both mate- and host-finding.