An invasive species is one that is not native to an ecosystem and whose introduction can cause economic or environmental harm to that ecosystem or to public health. Once established, invasives may impact biodiversity by out-competing native species for food and habitat.
Both Emerald Ash Borer (EAB) and the Asian Longhorned Beetle (ALB) are native to Asia. Both are wood-boring insects, whose worm-like larvae develop beneath the bark or within the wood of live trees, leaving tunnels under the bark and emergence holes. One to two years of infestation can kill a healthy tree.
The adult EAB has metallic green wing covers and a coppery-colored abdomen. EABs are small, roughly 1/2 inch-long and 1/8 inch wide. Since they were initially discovered near Detroit, Mich., and across the Detroit River in Windsor, Ontario, in 2002, infestations have destroyed almost 100 million trees in more than 19 states. A worst-case scenario, in which all species of ash are wiped out across North America, remains a distinct possibility.
Infestations are known to exist in Albany, Cattaraugus, Dutchess, Erie, Genesee, Greene, Livingston, Monroe, Niagara, Orange, Steuben, Tioga and Ulster counties.
Currently, a quarantine is in effect in all or part of 42 New York counties restricting the movement of ash nursery stock, any part of ash trees, firewood from any species, wood chips and bark mulch from any tree larger than 1 inch in two dimensions and other items.
Possible symptoms of EAB include dieback of the upper and outer crown, epicormic sprouting at the base and/or on the main stem, vertical splits in the bark and woodpecker feeding.
Definite signs include D-shaped emergence holes, S-shaped larval galleries or the insect itself, larvae or adult.
ALB attacks many species of hardwood trees, among them maple, ash, birch, poplar, elm, horse chestnut and willow. The insect is already responsible for the loss of more than 80,000 trees in the United States. It should be considered a serious threat to the maple, wood products, nursery and tourism industries.
ALB was first detected in North America on Norway, silver and sugar maples and horse chestnut trees in Brooklyn in 1996. It was subsequently found in Manhattan and Staten Island, as well as in Amityville and Islip on Long Island. ALB was also discovered in Chicago in 1998, in Jersey City in 2002, in Carteret, N.J., in 2004, in Worcester, Mass., in 2008, in Boston in 2010 and in Tate Township, Ohio, in 2011.
The insect was declared eradicated from the Chicago area and from Hudson County (Jersey City), N.J., in 2008, from Islip in 2011, and from Manhattan and Staten Island earlier this year. Nonetheless, a quarantine area in New York still remains for 58 square miles of Queens, 28 square miles of Brooklyn and 23 square miles of Nassau and Suffolk counties. In a recent statement made by State Agriculture Commissioner Darrel J. Aubertine, “the stakes are high but make no mistake. We are winning the fight against ALB in New York.”
In March of this year, New Jersey officials acknowledged eradication there had been successful, too. ALB has never been spotted in the Bronx or in New York State north of the city.
Early detection and rapid tree removal are crucial to the successful eradication of ALB. Currently, the only effective means of control is to remove infested trees as well as trees within the area of infestation that might host the beetle and chip or burn them. According to Paul J. Kurtz, the entomologist who led the successful eradication in the Garden State, only 11 infested trees were discovered in Linden, N.J., but 14,894, including many saplings, were removed.
Research at Cornell University’s Department of Entomology continues on developing new approaches for biological controls for ALB. The methodology is similar to that used to control a closely related orchard pest in Japan and involves the use of fiber bands permeated with a long-lasting insect pathogenic fungus placed around host trees. It is believed that adult beetles that come into contact with the fungal spores transfer the infection when mating. Infected females are able to lay only very few eggs before dying.
More information is available from your Extension office. Information about the ban on firewood movement can be found at www.dec.ny.gov/animals/28722.html.
Richard L. Gast, Extension program educator II, Horticulture, Natural Resources, Energy, agriculture programs assistant, Cornell Cooperative Extension of Franklin County, 355 West Main St., Suite 150, Malone, 12953. Phone 483-7403, fax 483-6214 or email firstname.lastname@example.org.