Clock ticking on hemlocks
It’s no secret I love hunting from hemlock trees. The thick evergreen foliage of a hemlock provides a great deal of natural cover for my stand and there is always an outward protruding branch on which I can hang my bow. During harsh weather like last year’s and so far this winter, stands of hemlocks provide a windbreak for deer that often determines if they live or die before spring.
But some may not know the hemlock may be going the way of the elm and American chestnut. Early in the 20th Century disease imported from abroad all but wiped out both species, which are considered two of North America's most impressive and important trees. In fact, there is hardly a city in America that doesn’t have an Elm Street. Scientists and foresters have known the hemlock has long been under attack by an imported insect that literally sucks the life out of the tree, and the insect's steady northward advance has raised a great deal of concern in much of New England and southern New York.
What really alarmed me it that I recently read the wooly adelgid has reached the forests of the Southern Tier, and this is really sad news because it may spell disaster for the area’s hemlock trees. The adelgid is a small insect with long mouth parts it uses to extract sap and nutrients from hemlock foliage, deterring tree growth. The insect also causes the hemlock’s needles to discolor and to eventually drop prematurely, thus further impairing tree health. Several years following infestation the tree dies. It’s assumed the insect is aided in spreading by the wind, birds, other wildlife and the movement of infested wood.
The most obvious sign of woolly adelgid infestation is the white woolly substance found on the base of the needles of hemlock trees. This white fuzzy stuff is actually a mass of eggs, and it can remain on the needles even after the eggs hatch. The young nymphs are very small, about the size of the period at the end of this sentence, and can be impossible to see, so the best indication of infestation is the fuzzy white egg masses at the base of the needles.
Currently, homeowners can treat an infected tree on their property by using a chemical insecticide, but treating large forested areas is impractical. As a consequence, the fate of large number of trees all across the state looks dismal.
As dire as all this sounds, there is some good news. Last season’s brutal winter and the cold and snow of this winter season may have killed off up to 98 percent of the adelgid population, and that can slow their spread for a while. But a long-term solution still needs to be found. Currently, scientists are looking at the possibility of using a biological control, namely a beetle native to the Far East that preys on the insect. The only problem is this beetle only produces one generation a year, so it could take a long time before it is widely distributed in nature. In addition, the cold that kills off the adelgid population also affects the beetles that feed on them. The hemlocks may not have that much time.