History of EAB

The Emerald Ash Borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is an invasive wood-boring beetle. Its native range is eastern Russia, northern China, Mongolia, Korea, Japan and Taiwan. The beetle's first North American populations were confirmed in the summer of 2002 in southeast Michigan and in Windsor, Ontario. Judging by the size of the infestations and the stage of damage to the infested trees, the beetle was likely introduced to the area in the early to mid 1990's. It is believed that the beetle was introduced into North America in ash wood used for shipping pallets and packing materials in cargo ships or shipping containers.

Emerald Ash Borers mating
Credit: Jared Spokowsky, New York State Department of Agriculture and Markets, Bugwood.org

EAB on leaf, note irregular edges caused by EAB feeding on leaves
PHOTO CREDIT: David Cappeart, Michigan State University
Since its introduction into North America, EAB has spread into 15 states (Illinois, Indiana, Iowa, Kentucky, Maryland, Michigan, Minnesota, Missouri, New York, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia and Wisconsin) and two Canadian provinces; Ontario and Quebec. EAB was first confirmed in New York in June 2009 near Randolph, in western Cattaraugus County. [Click to read NYS DEC / NYS DAM press release]

Emerald ash borers are strong fliers but adults typically fly less than 1/2 mile from the tree they emerged from. The natural spread of EAB infestations in North America is assumed to be about 2 miles or less per year but this depends on the infestation intensity. The rapid spread of the beetle since its North American introduction is most likely due to the transport of infested firewood, ash nursery stock, unprocessed ash logs, and other ash products. In an effort to slow the continued spread of EAB, both the Federal and State agencies have instituted quarantines of infested areas to regulate the transport of ash products. [Click to read about the NYS quarantine]

Impacts of the Emerald Ash Borer

The impacts of EAB infestation in New York will be severe. The NY Forest Health Advisory Council released a press release in July 2010 which describes the potential impacts and advises residents about what to do. Impacts and recommendations related to the recent confirmation of Emerald Ash Borer in Steuben and Ulster Counties, NY.

Although this was written in response to confirmation of EAB in Ulster and Greene Counties, the impacts and the recommendations are appropriate throughout NY State.

In the early stages of an invasion, Emerald Ash Borers are more attracted to stressed ash trees than to healthy ash trees. However, once EAB is established in an area, all ash trees greater than 1 1/2 inch (3 cm) in diameter are susceptible to attack. EAB infestation is always fatal to ash trees, even healthy ash trees, in approximately 2 to 4 years.

EAB kills ash trees when the larvae galleries in the phloem become so extensive that they prevent the flow of nutrients and water throughout the tree. This "girdling" of the tree starves all parts of the tree beyond the galleries, killing the tree from the top down.

Millions of ash trees have died or are dying from emerald ash borer attack in the United States since the beetle's introduction. More than 7.5 billion ash trees remain at risk.

In New York, ash was widely planted in urban and suburban areas to replace native elm trees that were killed by Dutch elm disease. The loss of large numbers of mature ash trees can have a devastating impact on the urban and suburban canopy, which can lead to localized temperature changes, increased energy costs, increased water usage for irrigation, increased stormwater runoff, and increased air pollution. The economic impact of removing and replacing thousands of dead trees in yards and along streets, and the potential public safety hazards and liability issues of dead ash trees along streets, in parks and in yards will be a challenge for communities and homeowners.

In natural forest settings, native ash trees are common (white, green and black ash make up almost 8% of all trees in NYS forests, 10% of all hardwood forests), providing habitat and a food source (seeds) for both birds and mammals.

Ash trees are valuable commercially, used for the manufacture of flooring, furniture, and shipping pallets, as well as that all-American device, the baseball bat. The almost 114 million board feet of ash lumber grown annually in the eastern U.S. is worth about $25 billion. Black ash is important to the culture of Native Americans, including NY's Akwesasne, as it is used for traditional basket making.

Split black ash basket by Ho-Chunk
artist Bertha Blackdeer, c. 1995
CREDIT: Wisconsin Historical Society,
Museum Object #1996.118.110
To read more about black ash in Native American basketry and to view a photograph of a black ash basket please visit the Wisconsin History website.