The devastating emerald ash borer, an invasive beetle that devours ash trees, may be headed for New Hampshire.

A state entomologist has warned that the ash borer is probably already in southern New Hampshire even though it hasn't been spotted yet, the Associated Press reported.

A "significant" infestation of the deep green bugs has been discovered by forest officials just over the Massachusetts state line, which is a few hundred feet away. The invasive insect has been spreading through Massachusetts with sightings in Concord and other communities.

Wisconsin and states in the Midwest have been preparing for the insect for the last month.

City workers in Madison marked 8,500 ash trees in late May with the ominous yellow dot, a spray-painted indicator of which trees will have to be removed, the Wisconsin State Journal reported. Around 12,500 additional trees on street terraces were scheduled to be treated with chemicals so officials could save as many as possible.

Residents in Ankeny, Iowa, have also steeling themselves against the invasive ash borer, which has destroyed more than 50 million trees in the country, according to The Des Moines Register.  

"Instead of the info just being doom-focused, we are really trying to give people options for how they can prepare," Iowa Department of Natural Resources Urban Forestry Specialist Shane Donegan told the Register.

The Asian beetle was recently spotted in Iowa City, according to The Gazette. While trees haven't shown signs of infestation, officials announced that one ash borer had been found, posing a threat to the state's 52 million rural ash trees and 3.1 million ash trees in urban areas.

"All we have so far is a beetle, and it is hard to know how it got here or where it came from," said Mark Vitosh of the Department of Natural Resources, as quoted by The Gazette.

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