Hemlock Woolly Adelgid

This pest is very prevalent in the Cape Cod landscape. The Canadian or eastern hemlock and the Carolina hemlock are it’s preferred hosts. Adult females are about 1.5mm long. They are black, but are usually covered with a white, cottony wax mass about 3mm in diameter. Overwintered immatures mature in spring, feeding on needles and settling on twigs at the base of needles . White waxy masses on trees spoil their appearance. Heavy infestations lead to needle yellowing, loss of vigor, premature needle drop, defoliation and death. Look for the white cottony wax masses on twigs throughout the year. This pest can be fairly easy to control in your landscape if it is detected early enough. The worst thing to do is to not deal with this pest when it arrives. Such populations will only lead to the demise of your trees and act as a reservoir for the pest for your neighbor’s trees. Hemlocks infested with the Hemlock Wooly Adelgid should be treated both at the beginning of the season and then again at the end of summer to insure proper control.