An emerald ash borer. Credit: Courtesy of the University of Maine via Maine Public

The invasive emerald ash borer has once again been detected in ash trees in the state.

The beetle is considered one of the most serious invasive species in Maine and is a serious threat to all three species of native ash trees in the state — green, white and brown, according to the Maine Department of Agriculture, Conservation and Forestry.

The beetles have been found in trees located in Porter, Saco and Westbrook, the DACF said. The finding of the beetles in the trees in Porter are the first to be detected in Oxford County.

The department said that the emerald ash borer has become abundant enough in those three counties that signs of the beetle can now be visible to passersby. Signs include bark flecking or ‘blonding’ from woodpecker feedings, vertical cracks in the bark, abnormal branching from the trunk, and diebeck of upper branches, it said.

The beetle is spreading faster in southern Maine than in the northern part of the state due to a massive front of the beetle spreading from New Hampshire and Massachusetts, the DACF said.

In October 2020, officials announced that ash trees purchased from Lowe’s stores last summer may have been infested with the destructive invasive beetle.

The trees were shipped to eight Lowe’s stores in Maine from a Connecticut nursery that obtained them from Maryland, where the emerald ash borer is widespread.

In mid-November, emerald ash borer infestations were confirmed in seven towns across the state: Gorham, Newfield, Ogunquit, Parsonsfield, Shapleigh, South Berwick and Van Buren.