In October, the Canadian Forest Service sent a research officer to Maine and New Hampshire to see firsthand an invasive insect that could take a huge toll on Canadian forests if we accidentally send it north.

Red pine scale (RPS) is a slow-moving Japanese insect deadly to American red pine trees (Pinus resinosa).

It has been in the U.S. for 80 years but, until 2012, was confined to plantations ranging from New Jersey to southern New England, where the USDA planted hundreds of thousands of acres of red pine as a hardy timber crop.

It wasn’t moving north into the native range of red pine because cold winters stopped it from spreading. That changed 12 years ago when it was found in Bear Brook State Park in Allenstown.

“The writing was on the wall,” said Will Guinn, administrator for the New Hampshire Forest Management Bureau, regarding how the Division of Forests and Lands decided to handle RPS when they found it in 2012.

New Hampshire is a natural home to red pine and has planted thousands of acres of the trees in plantations in the southern half of the state. Since RPS showed up here, it has been the state’s policy to cut and sell the impacted stands as quickly as possible, a move known as “salvage cutting.”

In 2012 after the Bear Brook discovery, New Hampshire cut and sold over 2 million red pine saw logs, one of the biggest movements of red pine logs in state record, beaten only by 2018, also because of RPS. The point isn’t just to cash in on the state’s timber investments, according to Guinn, but to suppress each outbreak rapidly.

“The thought was we couldn’t stop RPS, but we could slow it down if we moved very fast,” said Guinn.

One advantage foresters have over RPS is its slow speed. The egg-laying females can’t fly. Without help from the wind, birds or a vehicle, RPS’ range increases an average of only 1 mile per year. For comparison, the emerald ash borer (EAB) spreads 30 miles per year.

But there is concern that transporting these trees could accidentally spread RPS into Canada and elsewhere. From chestnut blight to ash borer, salvage cutting has been documented to spread forest pests before they are widespread, when containment is most effective and economical.

Most of the trees cut in the state because of RPS in 2012, according to Guinn and other sources, were shipped to Canada.

“We see a lot of log trucks go by,” said Skye MacMahon, 49, owner of Homegrown Lumber in Conway, which specializes in red pine flooring and gets its logs from a 20-mile radius. “It’s a major route to Canada.”

Contacted by the Canadian Invasive Species Centre, the Canadian Food Inspection Agency (CFIA) decided earlier this year to assess the risk of RPS in Canada and the potential of human transport to facilitate its spread. If the CFS recommends it, the CFIA may prohibit the importation of materials that are known to carry RPS.

In the past few years, several active researchers, including forest ecologists from Dartmouth College and UNH, whose work is, in part, funded by the USDA, have expressed concerns to public officials that an RPS invasion in the upper Great Lakes region could decimate the species there.

Red pine is native in New Hampshire, but the heart of the tree’s range is the Great Lakes from Quebec to Minnesota, where it is the state tree. Millions of acres of forest are dominated there by red pine.

To date, neither the USDA nor any of the nine impacted states have listed the insect as invasive and prohibited its transport. Non-native forest pests cost the U.S. public an estimated $14.4 billion in damages annually, and RPS’ toll on the forests and timber economies of the Great Lakes may prove catastrophic. Regulators in New Hampshire must weigh in the economic value of red pine plantations for the USDA, state and private interests, and the costs of restriction.

“We have to look at the value of the resource at risk, potential for success stopping it, cost of mitigation, and compare that to other problems,” wrote Kyle Lombard, forest health specialist for the state, who helped locate RPS sites to show the visitors from Canada. He offered his insights on managing forests with RPS, which seems imminent in New Brunswick, where the invader is now only 50 miles from the border.