Global Plant Protection News

Minn. Dept. of Natural Resources/AP/File

The Emerald ash borer is one of the non-native insects wreaking havoc in forests throughout the country.

By David Abel Globe Staff  May 10, 2016

Most arrive as stowaways on the wooden pallets and crates that help transport some 25 million shipping containers into the United States each year.

The invasive forest pests are ravaging forests and urban canopy throughout the country and cost property owners and communities, especially in the Northeast, as much as $2 billion a year, according to a study released Tuesday by the journal Ecological Applications.

The steady march across the continent of the Emerald ash borer, Asian longhorned beetle, hemlock wooly adelgid, and other non-native insects have been wreaking havoc that requires urgent solutions, said the authors of the study, which they called the most comprehensive review of forest pests in the US to date.

The pests, which also enter the country on plants that are destined for nurseries, have taken an especially harsh toll on trees in Massachusetts. Massachusetts has 57 types of pests, more than every other state but New York and Pennsylvania.

“The introductions of invasive pests that we continue to have is unacceptable,” said Dave Orwig , a forest ecologist at Harvard Forest in Petersham and one of 16 authors of the paper. “We’re just not doing enough.”

There are more than 400 forest pests in the country, and every state has invasive insects and pathogens. Louisiana has the fewest, with 12, while New York has the most, with 62.

Despite federal efforts to prevent their entry, such as having ports spray pallets with pesticides, between two and three new forest pests, on average, arrive in the country every year, Orwig said.

In Massachusetts, the pests include winter moths, which have devastated forests in the eastern part of the state; oak crypt gall wasps, which have been killing black oaks to the south and the islands; and a range of others, including the emerald ash borer, which has killed billions of dollars worth of ash trees across the country and was first found in Massachusetts in the Berkshires town of Dalton in 2012.

The state’s trees have also suffered from a range of pathogens, including butternut canker, dogwood anthracnose, Dutch elm disease, and beech bark disease.

Elsewhere in the state, hemlock wooly adelgid, a small insect, are killing many of the state’s hemlock trees, while Asian longhorned beetles have devastated red maples, especially in Worcester, where authorities have removed more than 34,000 trees at a cost of about $150 million, Orwig said.

“It looked like a hurricane had struck the city,” he said of Worcester. “It will take decades or more for the community to recover the benefits of the trees.”

David Abel can be reached at dabel@globe.com. Follow him on Twitter @davabel.