The Maine Department of Agriculture, Conservation and Forestry has announced a formal quarantine on emerald ash borer and material that may harbor it. The quarantine area includes all of York County and the northeastern corner of Aroostook County. FILE PHOTO

AUGUSTA — As expected, the Maine Department of Agriculture, Conservation and Forestry has announced a formal quarantine on emerald ash borer and material that may harbor it and the quarantine area includes all of York County and the northeastern corner of Aroostook County.

An emergency order has been in place to limit movement of infested ash from areas where the pest has been found since those discoveries.

In late February, the Maine Forest Service, with support of landowners and assistance from Central Maine Power and Lucas Tree Experts, collected branches from ash trees along roadsides in Acton, Lebanon and Berwick. Forest Service staff peeled the bark off these branches to look for signs of emerald ash borer.

Live emerald ash borer larvae were found on two of the trees sampled, one each from the towns of Acton and Berwick. Although these trees still appear completely healthy, they are infested with the invasive pest. These were the first emerald ash borer found within trees in York County as the previous finds in Acton and Lebanon were adults that had flown into the traps.

Given this and the previous trapping survey, the Maine Forest Service confirmed that the emerald ash borer is established, at least sporadically, within three miles of the New Hampshire border for at least 17 miles between Acton and Berwick and it is almost certain that they have spread further than this area.

Quarantine rules prohibit movement of ash nursery stock from the quarantine area, and regulate the movement of hardwood firewood, hardwood chips and other ash products with bark, such as logs and pulp, and untreated ash lumber. Maine Department of Agriculture, Conservation and Forestry staff, in partnership with the U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Plant Protection and Quarantine are working with the public and impacted industries to ensure compliance with the quarantine.

“A quarantine can help slow the spread of this destructive insect into uninfested areas,” said Maine State Entomologist Allison Kanoti. “That gives businesses, Native American craftspeople and artists that use ash as well as homeowners, landowners and municipalities who care for ash across the state additional time to consider their options and make plans for a future with the Emerald Ash Borer.”

In all likelihood, that future will include far fewer ash trees. Maine forests currently contain have more than 400 million white, green, and brown ash trees at risk.

Kanoti said ash is also an important street tree in towns and cities and the emerald ash borer is an invasive wood-boring beetle that attacks ash trees by disrupting the flow of water and nutrients causing the tree to die.

Native ash trees have little resistance to attack, and often die within a few years of initial arrival of the beetle. The pest was first discovered in North America in 2002. Since its arrival, it has killed hundreds of millions of ash trees.

According to Kanoti, white ash shows some resistance to and tolerance of attack by the invasive pests.

“A fraction of those trees may be able to survive in the presence of the Emerald Ash Borer,” she said. “The U.S. Department of Agriculture has been working on a program to provide ash with another form of defense, tiny wasps from Asia that attack the eggs or young of the Emerald Ash Borer and may eventually bring their populations to a tolerable level.”

State officials warn that even with defense measures, the borer will devastate ash trees in areas where it spreads into. Damage may include harm to infrastructure such as power lines and hazards to people related to the deterioration of ash trees attacked by this insect.

They say that the goal of the quarantine is to slow the spread of the insect to delay impacts to the ecosystem, native culture and economy.

The ash borer is a destructive and invasive pest that was initially detected in Michigan in 2002 prompting a federal quarantine in 2003 to restrict movement of potentially infested material. Native to Asia, it’s thought to have arrived in the United States in solid-wood packing material.

Through the end of last year, it has been found in 35 states, and four Canadian provinces and has cost municipalities, property owners, nursery operators and forest products industries hundreds of millions of dollars as ash trees infested with ash borers typically die within two to three years.

— Executive Editor Ed Pierce can be reached at 282-1535 or by email at [email protected]

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