Development of a Host-Based Semiochemical Lure for Trapping Emerald Ash BorerAgrilus planipennis(Coleoptera: Buprestidae)

Bark volatiles from green ash Fraxinus pennsylvanica were tested for electrophysiological activity by Agrilus planipennis using gas chromatographic-electroantennographic detection (GC-EAD) and for behavioral activity using baited purple traps in Michigan.GC-EAD analysis of the headspace volatiles of bark tissue samples from 0-and 24-h-old fully girdled (stressed) ash trees showed that the latter had elevated sesquiterpene levels.Six of the elevated compounds consistently elicited antennal responses by both male and female A. planipennis.Five of the antennally active compounds were identiÞed as ␣-cubebene, ␣-copaene, 7-epi-sesquithujene, trans-␤-caryophyllene, and ␣-humulene (␣-caryophyllene).The sixth EAD-active compound remains unidentiÞed.We monitored capture of adult A. planipennis on traps baited with several combinations of ash tree volatiles.Treatments included two natural oil distillates (Manuka and Phoebe oil) that were found to contain, respectively, high concentrations of four and Þve of the six antennally active ash bark volatiles.A four-component leaf lure developed by the USDA Forest Service and Canadian Forest Service was also tested.In three separate Þeld studies, Manuka oilÐ baited traps caught signiÞcantly more adult beetles than unbaited traps.Lures designed to release 5, 50, and 500 mg of Manuka oil per day all caught more insects than unbaited traps.In a Þeld test comparing and combining Phoebe oil with Manuka oil, Phoebe oilÐ baited traps caught signiÞcantly more beetles than either Manuka oilÐ baited traps or unbaited traps.We hypothesize that the improved attractancy of Phoebe oil to A. planipennis over Manuka oil is caused by the presence of the antennally active sesquiterpene, 7-epi-sesquithujene. KEY WORDS Buprestidae, bark volatiles,