An insect that kills ash trees has spread to 15 cities since it was discovered in Rhode Island three years ago, according to the State Department of Environmental Management.
Emerald ash drills are responsible for the decline and death of millions of ash trees in North America, according to the DEM. Dead ash trees have been reported in some Rhode Island communities, although the DEM did not provide a number in a press release.
The Asian-native insect was first found in Rhode Island in 2018 when small numbers of the beetles were discovered in Burrillville, Cumberland, Hopkinton, Lincoln, Providence, and Westerly.
They have since been found in greater numbers and in nine additional parishes: Charlestown, Foster, Glocester, North Smithfield, Scituate, Smithfield, South Kingstown, West Greenwich, and Woonsocket, according to DEM.
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Emerald ash drills threaten all types of ash in Rhode Island, including white ash, green ash, and black ash, according to DEM. Ash trees make up about 1% to 2% of Rhode Island’s forests, according to the DEM.
According to the DEM, ash trees are also popular in urban environments because of their winter hardiness, tolerance to pollutants and the shade they offer.
The beetles are dangerous for ash trees because their larvae feed on the inner bark tissue of the trees. Once trees are infested, they can die within three to five years, says the DEM.
Individual landscape trees can be treated, but there are no proven methods of combating insects in forests, according to the DEM. URI researchers are among those trying to find a way to control the errors. The university is testing the use of parasitic wasps to slow the spread, according to the DEM.
The insects can fly short distances, but according to the DEM, humans helped them spread by moving firewood and other infested material. According to the DEM, campers and fire pit users can slow the spread by only buying and burning local firewood.
The DEM says it is continuing to work with URI to determine the extent of the infestation.
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