Skip to Main Content
Hemlock Woolly Adelgid (Hemiptera: Adelgidae): A Non-Native Pest of Hemlocks in Eastern North AmericaAuthor(s): S. Limbu; M.A. Keena; M.C. Whitmore
Source: Journal of Integrated Pest Management. 9(1): 27: 1-16.
Publication Series: Scientific Journal (JRNL)
Station: Northern Research Station
Download Publication (2.0 MB)
DescriptionHemlock woolly adelgid, Adelges tsugae Annand, is an invasive insect species in eastern North America that was accidentally introduced from southern Japan. It is the single most important pest of hemlocks in eastern North America and has a severe impact on the two susceptible species: eastern hemlock, Tsuga canadensis (L.) Carriere (Pinales: Pinaceae) and Carolina hemlock, Tsuga caroliniana Engelmann (Pinales: Pinaceae). Since the first report of hemlock woolly adelgid in Virginia in 1951, it has been slowly but steadily increasing its range. Recent establishments outside the contiguous range in Michigan and Nova Scotia have also occurred. At the stand level, hemlock trees are being replaced by hardwood trees in eastern North America, impacting some critical ecosystem processes. Several institutions are actively researching ways to protect the existing hemlock stands from further damage and to restore the ecosystems impacted by their loss. Although several control options for hemlock woolly adelgid have been developed, none are completely effective on their own, so a combination of all available control strategies is being used in an effort to save the existing hemlock stands. High-value hemlocks are being protected using chemicals, while a suite of predators is being released in forested areas. However, biological control has not provided immediate protection for heavily infested trees, so options for restoring hemlocks (hybrids with Asian species and punitively resistant stock) and finding viable replacements are being evaluated.
- Check the Northern Research Station web site to request a printed copy of this publication.
- Our on-line publications are scanned and captured using Adobe Acrobat.
- During the capture process some typographical errors may occur.
- Please contact Sharon Hobrla, email@example.com if you notice any errors which make this publication unusable.
CitationLimbu, S.; Keena, M.A.; Whitmore, M.C. 2018. Hemlock Woolly Adelgid (Hemiptera: Adelgidae): A Non-Native Pest of Hemlocks in Eastern North America. Journal of Integrated Pest Management. 9(1): 27: 1-16. https://doi.org/10.1093/jipm/pmy018.
KeywordsAdelges tsugae, hemlock, Tsuga spp., invasive species
- Impacts of hemlock decline and ecological considerations for hemlock stand restoration following hemlock woolly adelgid outbreaks
- Effects of the removal of overstory hemlock from hemlock-dominated forests on eastern redback salamanders
- The aftermath of an invasion: Structure and composition of Central Appalachian hemlock forests following establishment of the hemlock woolly adelgid, Adelges tsugae
XML: View XML