I'm often asked if the Hemlock Woolly Adelgid is still feeding on Hemlocks in Highlands. I found this tree (not on the golf course, thankfully) that is infested with this insect. The white cottony egg masses are signs of an adelgid infestation.
The presence of HWA can be identified by its egg sacs, which resemble small tufts of cotton clinging to the underside of hemlock branches. Hemlocks stricken by HWA frequently become grayish-green rather than the dark green of healthy hemlocks. In North America, the hemlock woolly adelgid asexually reproduces and can have two generations per year. In its native Asian habitat is a third winged generation called Sexupera; this generation's reproduction requires a species of spruce that is not found in the Eastern United States and therefore dies there. Between 100 and 300 eggs are laid in the woolly egg sacs beneath the branches. Larvae emerge in spring and can spread on their own or with the assistance of wind, birds and/or mammals. In the nymph stage, the adelgid is immobile and settles on a single tree.
The hemlock woolly adelgid feeds on the phloem sap of tender hemlock shoots. It may also inject a toxin while feeding. The resulting desiccation causes the tree to lose needles and not produce new growth. In the northern portion of the hemlock's range, death typically occurs four to ten years after infestation. Trees that survive the direct effects of the infection are usually weakened and may die from secondary causes
