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Forester Jeff Wiegert, of the New York State Department of Environmental Conservation, removes emerald ash borer larvae from an ash tree at Esopus Bend Nature Preserve in Saugerties, N.Y. New Hampshire is looking at another summer of battling the emerald ash borer, the invasive beetle that's destroyed ash trees in 26 states. It's been found in at least 16 towns in New Hampshire and officials say it is spreading.

CONCORD, N.H. >> New Hampshire is looking at another summer of battling the emerald ash borer, an invasive beetle that has destroyed ash trees in 26 states.

It's been found in at least 16 towns in New Hampshire and officials say it is spreading.

The emerald ash borer, originally from China, has killed millions of ash trees nationwide since being discovered in Michigan in 2002. It's often spread by people transporting firewood. Many states, including New Hampshire, have quarantines for out-of-state firewood. Vermont just started one.

The metallic green insect's larvae feed just below the bark and adults go after the leaves. Ash trees where the pest is found typically die within two to five years.

Gov. Maggie Hassan declared May 22-28 Emerald Ash Borer Awareness Week, encouraging landowners and communities to learn more about the bug and prepare for them.

Here's what's known about the beetle in New Hampshire:

WHAT'S AFFECTED:

Ash is a commonly used landscape tree and makes up about six percent of New Hampshire's northern hardwood forests. The emerald ash borer was first found in New Hampshire in 2013, and it has spread to 16 towns. The most intense outbreak has been in the area of Canterbury and Loudon. Four counties — Belknap, Hillsborough, Merrimack and Rockingham — are under quarantine for movement of ash wood.

What to look for


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Signs that the emerald ash borer has visited your ash tree include "blonding" of the bark. That happens when woodpeckers forage for insects beneath the bark and chip away the top layer. That creates a lighter color than surrounding bark.

How to treat it

New Hampshire has been releasing two types of wasps since 2013 that have shown some success in preying on emerald ash borers. Forestry officials plan to release more throughout the summer. The wasps are among four species that have been released in 24 states where the ash borer has been detected. In New Hampshire, officials have found that eggs from the adult wasps have hatched and have fed on emerald ash borer larvae on their own, so the hope is to create a self-sustaining population of the wasps.

This will be the second summer that forestry officials put up horizontal chains of bright green funnels designed to attract and catch the emerald ash borer. They seem to have done slightly better than boxy, purple traps that have been hung for the past few years.

Landowners can consider treating their trees with insecticides when an infested area is within 10 miles of their property. They can use products containing imidacloprid or dinotefuran.

Firewood

With the camping season underway, New Hampshire residents are advised to buy firewood from a local supplier and burn it in the same area. Firewood can't be moved from the four quarantined counties. New Hampshire also has a quarantine for out-of-state firewood.

Kyle Lombard, forest health specialist with the New Hampshire Division of Forests and Lands, says the emerald ash borer has not reached the major ash forests in the northern part of the state, and that's because people have been following the firewood rules.

Vermont, which is concerned about the Asian longhorned beetle and the emerald ash borer but hasn't reported them yet, just started its first year out-of-state firewood quarantine. Campers transporting firewood to Vermont must have a receipt or label certifying that the wood has been heat-treated to a core temperature of 160 degrees for at least 75 minutes.