Chemical ecology of the invasive beech leaf mining weevil (Orchestes fagi L.) in Nova Scotia, Canada
LE3 .A278 2014
Bachelor of Science
The beech leaf mining weevil, Orchestes fagi L. (Curculionidae: Curculioninae: Ramphini) is a common pest of beech trees, Fagus sylvatica L. (Fagaceae) in Europe that has recently become established in Nova Scotia, Canada, where it is damaging American beech (Fagus grandifolia Ehrh.). The objective of this study has been the development of effective tools to monitor the spread and impact of this exotic invasive species. A combination of Y-tube behavioural bioassays and electrophysiological studies (electroantennography (EAG) and gas chromatographic-electroantennographic detection (GC-EAD)) were used to identify potential attractive materials. Putative attractants were also deployed in field trap bioassays. EAGs suggested antennae were sensitive to green leaf volatiles as well as putative O. fagi pheromones collected through solid-phase micro-extraction (SPME). Host preference trials, via Y-tube olfactometer bioassays, indicated equal preference by male and female adults for beech, raspberry, cherry, and apricot leaves as well as a significant preference for apple leaves over beech. Trapping bioassays at two field sites in Halifax clearly showed that yellow sticky cards were more efficient at trapping O. fagi than were boll weevil traps, but putative attractants did not significantly improve trap catch. Further research will be required to define efficient attractants for use in lure development. This study provides evidence that O. fagi life history is similar in North America in comparison to its native European range with a period of approximately 5-6 weeks in early summer in association with its primary host (American/European beech). Further research on presence and habits on alternative hosts outside this period and/or inactivity due to overwintering will be required to fully understand the North American life history of O. fagi.
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