Hemlock Wooly Adelgid



White cottony sacs of the base of the needles are good evidence of a hemlock woolly adelgid infestation. These sacs resemble the tips of cotton swabs. They are present throughout the year, but are most prominent in early spring.


The hemlock woolly adelgid, Adelges tsugae, has been in the United States since 1924. This introduced insect, believed to be a native of Asia, is a serious pest of eastern hemlock and Carolina hemlock. In the eastern United States, it is present from the Smoky Mountains, north to the mid-Hudson River Valley and southern New England. The hemlock woolly adelgid feeds during all seasons with the greatest damage occurring in the spring. It is dispersed by wind, birds and mammals. By sucking sap from the young twigs, the insect retards or prevents tree growth causing needles to discolor from deep green to grayish green, and to drop prematurely. The loss of new shoots and needles seriously impairs tree health. Defoliation and tree death can occur within several years.


Chemical Control: Bayer Advanced™ Tree & Shrub Insect Control Concentrate is the only tree and shrub insect control that provides 12 months of protection with one application. It contains the proprietary MERIT® systemic insecticide for maximum, rainproof results. No spraying is required; just mix and pour at the base of the tree or shrub. It controls many insect pests, including adelgids.