The presence of invasive insects is not new, Kritsky said. And not all invasive insects are bad. The honeybee is an example of a successful invasive insect, he said.
“We’re an international community shipping things all over the world and this is going to lead to the introduction of exotic pests,” Kritsky said.
The hemlock woolly adelgid is native to Japan and was first discovered in the western United States in the 1920s. It was first reported in the eastern portion of the country in 1951 near Richmond, Virginia, and in Meigs County, Ohio, in 2012.
The insect is primarily transported by birds, wind and nursery stock. For this reason, the nursery industry needs to be aware, if bringing in hemlocks for landscaping, of the origin of their shipments, Kritsky said.
Homeowners can help protect the trees in their landscape by doing regular inspections, he said. If concerns exist, Kritsky encourages homeowners to contact a tree professional or a representative from the Ohio Department of Natural Resources for an inspection and development of an action plan.
It feeds on Canadian Hemlock, Tsuga Canadensis. The insect was discovered last summer feeding on a mature stand of Hemlocks on Little Mountain on a property located on the grounds of Holden Arboretum. Although it is uncertain how the adelgid got there, it is thought that it arrived on birds migrating north.