Mitochondrial DNA from Hemlock Woolly Adelgid (Hemiptera: Adelgidae) Suggests Cryptic Speciation and Pinpoints the Source of the Introduction to Eastern North America

Evaluating a potential area-wide IPM strategy for managing hemlock woolly adelgid in the eastern United States

“…species worldwide with the exception of eastern (T. canadensis Carriére) and Carolina (T. caroliniana Engelmann) hemlock. It is an obligate herbivore of hemlock trees, and due to its recent introduction to the eastern United States, it has become a significant pest of eastern and Carolina hemlocks (Havill et al 2006, Havill et al 2011). …”

“…and northern Japanese hemlock (T. diversifolia Maxim.(Mast.)) as secondary hosts (Havill et al 2006). The inverse of holocyclic is anholocyclic, i.e.…”

“…Estimates also stretch back to nearly 5 mya (million years ago) during the last glacial maximum (LGM) (Havill and Foottit 2007); however, this estimate is considered less valid today due to limited archaeological evidence (Havill et al 2016). In western North America, unlike in the East, HWA populations are kept below damaging levels through a combination of evolved host tree resistance and a complex of native predators (Havill et al 2006, Kohler et al 2008, Havill et al 2016.…”

“…This was likely the result of an earlier, accidental introduction from Japan (Havill et al 2006, Havill andFoottit 2007). It is unknown who is responsible for introducing HWA; however, it is hypothesized that it arrived on Japanese hemlocks that were imported for an Asian garden located near Richmond, Virginia.…”

Hemlock woolly adelgid alters fine root bacterial abundance and mycorrhizal associations in eastern hemlock

“…China (Havill et al, 2006), it can kill even mature eastern hemlocks in as little as four years; few 81 heavily-infested trees survive longer than ten years (Orwig and Foster, 1998 Preisser et al, 2011). We assessed the rhizosphere of eastern hemlocks in a subset of the stands 98 described above.…”