the hemlock wooly adelgid is native to east asia.
where is the hemlock wooly adelgid native to?
east asia
hemlock woolly adelgid ("adelges tsugae"), or hwa, is member of the sternorrhyncha suborder of the order hemiptera and native to east asia. it feeds by sucking sap from hemlock and spruce trees ("tsuga" spp.; "picea" spp.). in its native range, hwa is not a serious pest because populations are managed by natural predators and parasitoids and by host resistance. in eastern north america it is a destructive pest that threatens the eastern hemlock ("tsuga canadensis") and the carolina hemlock ("tsuga caroliniana"). hwa is also found in western north america, where it has likely been present for thousands of years. in western north america, it primarily attacks western hemlock "tsuga heterophylla" and has only caused minor damage due to natural predators and host resistance. accidentally introduced to north america from japan, hwa was first found in the eastern united states near richmond, virginia, in 1951. the pest is now found from northern georgia to coastal maine and southwestern nova scotia. as of 2015, 90% of the geographic range of eastern hemlock in north america has been affected by hwa.
hemlock woolly adelgid
in a 2009 case study, entomologists from the u.s. forest service, cornell university, and the university of massachusetts-amherst released 900 "laricobius nigrinus" beetles into a stand of adelgid-infested hemlocks near lansing, new york. "l. nigrinus", which is native to the pacific northwest, naturally preys on the hemlock wooly adelgid. the particular site near lansing was chosen because its hemlocks are only lightly infested with the woolly adelgid, and enough trees are found to sustain a long-term study. the site will be left untreated with pesticides for 10 years to study how well the "l. nigrinus" beetles become established; if the experiment proves successful, researchers expect the population will take two to three years to build to levels where they can be readily detected.
tsuga canadensis