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Abstract
The eastern North American native hemlock species,
T. canadensis [L.] Carriere and
T. caroliniana Engelm., are highly susceptible to injury from the hemlock woolly adelgid (HWA),
Adelges tsugae, while the Asian species,
T. chinensis (Franch.) E. Pritz,
T. diversifolia (Maxim.) Mast., and
T. sieboldii Carriere are reported to show more resistance (Del Tredici and Kitajima 2004, McClure 1992 and 1995, and Montgomery 1999). The U.S. National Arboretum initiated a hemlock breeding program in the 1990s to assess the potential for controlled hybridization among different hemlock species utilizing both the HWA-susceptible eastern species and the HWA-resistant Asian species.
Citation
Bentz, S.E.; Montgomery, Michael E.; Olsen, Richard T. 2008. Resistance of hemlock species and hybrids to hemlock woolly adelgid. In: Onken, Brad; Reardon, Richard, comps. Fourth Symposium on hemlock woolly adelgid in the eastern United States; 2008 February 12-14; Hartford, CT. FHTET 2008-01. Morgantown, WV: U.S. Forest Service, Forest Health Technology Enterprise Team: 137-139.
