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Response of male and female emerald ash borers, Agrilus planipennis, to green leaf volatile and sesquiterpene lures
GG Grant1, KL Ryall1, DB Lyons1 & TM Poland2
1Great Lakes Forestry Centre, Canadian Forest Service, Sault Ste. Marie, ON, P6A 2E5 Canada
2USDA Forest Service, Northern Research Station, East Lansing, MI 48823, USA
Abstract
We conducted several trapping experiments in 2008 and 2009 on the emerald ash borer (EAB) in green ash plantations in southern Ontario, Canada, to compare the attractiveness of the green leaf volatile (GLV) lure (Z)-3-hexenol (Z3-6:OH) (7.6 - 80 mg/d) against standard Manuka oil (50 mg/d) and Phoebe oil (50 mg/d) pouch lures placed in green prism traps in the ash canopy and purple traps on ash trees at the 1.5 m level. GLVs are typical emissions from ash foliage on which EAB adults feed, whereas sesquiterpenes are typical emissions from ash bark where females oviposit. As fatty acid derivatives and terpenoids, respectively, they represent two different classes of stress volatiles. Total catch by the Z3-6:OH lure was superior to catches by the sesquiterpene lures when placed in light green traps in the ash canopy and was equal or better than Manuka oil in purple traps at 1.5 m. Manuka oil and Phoebe oil baited traps tended to catch both male and female beetles almost equally, whereas catches with Z3-6:OH baited traps showed a strong male bias consistent with previously obtained antennal responses in GC-EAD bioassays. The differential effect of various lures on the sexes deserves further investigation. Adding other currently available GLV lures (i.e. C6 alcohols, aldehydes or acetates) in various combinations with Z3-6:OH, failed to improve catches. We conclude that light green prism traps baited with (Z)-3-hexenol should be considered for area-wide detection surveys for EAB. In an attempt to extend the range of possible GLV blends that can be tested against EAB, we evaluated a newly developed autonomous pump, Pher-Emit (Med-e-Cell, San Diego, CA) that allows greater control over blend composition and blend release rates.
References
de Groot P, Grant GG, Poland TM, Scharbach R, Buchan L, Nott RW, MacDonald L and Pitt D. 2008. Electrophysiological response and attraction of emerald ash borer to green leaf volatiles (GLVs) emitted by host foliage. J. Chem. Ecol. 34: 1170-1179.
Grant GG, Ryall KL, Lyons DB, and Abou-Zaid MM. 2009. Differential response of male and female emerald ash borers (col., Buprestidae) to (Z)-3-hexenol and manuka oil. J. Appl. Entomol. (on line) doi : 10.111/j1439-0418.2009.01441.x
Response of the invasive emerald ash borer, Agrilus planipennis, (Col., Buprestidae) and native bronze birch borer (A. anxius) to volatiles of their respective hosts in North America.
GG Grant, KL Ryall, MM Abou-Zaid, DB Lyons
Great Lakes Forestry Centre, Canadian Forest Service, 1219 Queen St. E., Sault Ste. Marie, ON Canada P6A 2E5
The emerald ash borer (EAB) is an invasive Asian beetle killing millions of ash trees ((Fraxinus spp.; Oleaceae) across eastern North America. Adult borers feed on ash foliage. In situ sampling of foliage volatiles followed by GC-EAD bioassays, revealed 8 green leaf volatiles (GLVs) with consistent EAD activity, with Z3-6:OH producing the largest responses, particularly from male antennae. Field tests conducted in 2008 confirmed that Z3-6:OH lures (7.6 – 80 mg/day) in purple prism traps at 1.5 m or in light green traps in the ash canopy were significantly attractive to EAB and showed a strong male bias consistent with GC-EAD responses. Other GLVs combined with Z3-6:OH have failed to enhance catches. Manuka oil lures, a source of attractive sesquiterpenes emitted by ash bark, were generally less attractive than Z3-6:OH lures, and there was no consistent sexual bias in trap catches. Field tests in 2009 involving more complex GLV lure mixtures are being evaluated with a novel autonomous pump (Pher-Emit). Complex lure blends are easily accommodated with the pump design, which also allows a range of release rates, providing greater flexibility than current bubble cap or pouch technologies.
GC-EAD responses of the native bronze birch borer, Agrilus anxius, to foliage volatiles from its birch (Betula spp.; Betulaceae) hosts indicated that GLVs were also strong stimuli for this species. Field tests are being conducted in 2009 with both GLVs and manuka oil lures in prism traps of various colors. Results thus far show little similarity with EAB.
