Submitted to: Environmental Entomology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/14/2008
Publication Date: 2/1/2008
Citation: Crook, D.J., Khrimian, A., Fraser, I., Francese, J.A., Poland, T.M., Mastro, V.C. 2008. Electrophysiological and behavioral responses of Agrilus planipennis (Coleoptera: Buprestidae) to host bark volatiles. Environmental Entomology. 37(2):356-365. Interpretive Summary: An invasive insect species, emerald ash borer, established recently in North America, is a serious forest pest destroying a variety of ash trees. An attractant-baited survey trap capable of detecting emerald ash borer adults at low densities would be a potentially useful tool for identifying new infestations and monitoring management areas. Using a special technique (gas chromatography coupled with electroantennographic detection) we found that both male and female emerald ash borer are capable of detecting though their antennae volatile chemicals released by the bark of green ash. Among these chemicals are compounds present in an essential oil called manuka oil. Field trapping experiments with an manuka oil suggest that bark chemicals play an important role in host location for both male and female emerald ash borer and show potential for use as attractants in monitoring programs. These results are of interest to other chemists and entomologist involved in the monitoring and control of emerald ash borer, and also to state and federal regulatory agencies, APHIS and U.S. Forest Service.
Technical Abstract: 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 USA. GC-EAD analysis of the headspace volatiles of bark tissue samples from non-girdled (healthy) and 24-hr-old fully girdled (stressed) ash trees revealed that the latter had elevated sesquiterpene levels. Six of the elevated compounds in stressed bark samples consistently elicited antennal responses by both male and female A. planipennis. Five of the EAD-active compounds were identified as ÿ-cubebene, ÿ-copaene, 7-epi-sesquithujene, trans-ÿ-caryophyllene and ÿ-caryophyllene (humulene). The sixth EAD-active compound remains unidentified. Field trapping experiments with an essential oil (manuka oil) containing ÿ-cubebene, ÿ-copaene, trans-ÿ-caryophyllene and ÿ-caryophyllene suggest that bark sesquiterpenes play an important role in host location for both male and female Agrilus planipennis and show potential for use in semiochemical based monitoring programs.