Recently, HWA was inadvertently shipped to New Hampshire on nursery stock from infested states. In addition, in two cases, the insect was found on nursery stock that had been planted four years ago. The infested trees were located and the infestations were eliminated. What to Look For Hemlock woolly adelgid, at this time, can not be controlled in the forest. It is therefore extremely important to look for this insect and control it before it reaches the forest.
Early detection is critical to prevent spread.
Look for white cotton tufts at the base of needles on the underside of twigs and branches. Inspect hemlocks with unhealthy grayish-green needles, premature needle drop and twig dieback.