Many senior citizens can readily recall the magnificent American elm trees that once dotted our countryside and villages. Dutch Elm Disease, an invasive spread by the Elm Bark Beetle from Asia, decimated these beautiful shade trees in a matter of a few decades. Now we’re faced with even more invasive species that threaten to destroy our indigenous forests.
Thanks primarily to the global economy which sees increasingly more commerce, both legal and illegal, between continents, the list of invasive species in the United States is mind boggling, at last count In the U.S. there are more than 52,000 invasive species today, and the number continues to increase annually despite efforts by government to stop the introductions of alien species to our shores. Whether land or water based, these invasive species have few natural enemies to control them. The latest is the Emerald Ash Borer.
The NYS Department of Environmental Conservation (DEC), along with other federal and state agencies, is setting baited traps in ash trees across upstate New York in an effort to search for possible infestations of the Emerald Ash Borer (EAB), a tree-killing beetle. The public will soon be seeing the purple prism traps deployed in treelines throughout New York, with a concentration in areas adjacent to neighboring states and Canadian provinces that have already detected this potentially devastating invasive species.
It has been documented that a main route that enables this insect, as well as other invasive species, to spread is from moving lumber and firewood from one place to another. That is why in 2008, New York adopted regulations that ban untreated firewood from entering the state and restricts intrastate movement of untreated firewood to no more than a 50-mile radius from its source.
New York has more than 900 million ash trees, representing about 7 percent of all trees in the state, and all are at risk should this invasive, exotic pest become established. Many communities are at particular risk because ash was widely planted as a street tree after Dutch elm disease (another invasive) killed many urban trees.
The Hemlock Woolly Adelgid is native to parts of Asia and was first discovered in New York in 1985. It is in the family Adelgidae, which is related to aphids. The Adelgid uses long mouthparts to extract sap and nutrients from hemlock foliage, this prevents free 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. Infestation is usually fatal to the host after several years. Valued plantings of the shade-loving Eastern hemlock (Tsuga canadensis) can be ravaged by the Hemlock Wooly Adelgid, and the natural stands of hemlock in the forests and parks in upstate New York would be greatly affected if the pest spreads to those locations. The wind, birds, other wildlife and the movement of infested host material by humans are all factors in the dispersion of the adelgid. Currently 20 NY counties are infested with the Hemlock Wooly Adelgid.
The Gypsy Moth (GM) is native to Europe. It was first detected in the United States in 1869 in Massachusetts. Several Gypsy moth introductions have been detected and eradicated since the 1970s. The Gypsy Moth is a dangerous pest because the caterpillars have voracious appetites for more than 500 species of trees and shrubs, posing a danger to North America’s forest habitats. The caterpillars defoliate, or strip the tree of leaves, which kills the tree and/or leaves it vulnerable to disease and other pests. The caterpillars feed mainly on hardwood trees, such as oaks, aspen, birch and willow.
