Canadian Forest Service Publications
Hitching a ride: firewood as a potential pathway for range expansion of an exotic beech leaf-mining weevil, Orchestes fagi (Coleoptera: Curculionidae). 2017. Morrison, A.; Sweeney, J.D., Hughes, C.C., and Johns, R.C. The Canadian Entomologist 149: 129-137.
Issued by: Atlantic Forestry Centre
Catalog ID: 39563
CFS Availability: PDF (download)
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We investigated the potential for human-mediated range expansion of an exotic beech leaf-mining weevil, Orchestes fagi (Linnaeus) (Coleoptera: Curculionidae: Curculioninae: Rhamphini) (formerly known as Rhynchaenus fagi) on timber or firewood, which for eight to nine months of the year may harbour adults in diapause. In both relatively low-density and high-density populations, adults were found on the base, middle, and upper boles of the primary host, American beech (Fagus grandifolia Ehrhart; Fagaceae), as well as red maple (Acer rubrum Linnaeus; Sapindaceae) and red spruce (Picea rubens Sargent; Pinaceae) in the vicinity. Comparatively few individuals were found on tree branches, or in the moss, duff, or soil collected beneath beech trees. Overwintering adults appeared to favour parts of trees with relatively high bark roughness. Our study suggests that, between the months of July through May, any woody stems near areas having O. fagi outbreaks are likely to harbour adults. Moreover, as all of the trees studied are common sources of timber or firewood, the harvest and transport of wood from these areas may facilitate outbreak spread; this may explain the multiple, distantly distributed populations of O. fagi that have been reported in eastern Nova Scotia, Canada in recent years.
Plain Language Summary
The beech leaf-mining weevil (Orchestes fagi (L.)) is an exotic pest of American beech that causes serious defoliation in Nova Scotia. We conducted field studies to determine where adults overwinter and to what extent their spread across Atlantic Canada and neighboring regions has been facilitated by transport of timber and firewood. Our results indicated that trunks of all mature hardwoods and softwoods can harbor overwintering adults between the months of August and May and that harvest and transport of this wood during this period can help spread the pest.