About 50 years ago, a legendary spruce budworm outbreak devastated Maine's North Woods.
The native caterpillars devoured millions of acres of spruce and fir trees and left behind a vast landscape of skeletal trunks.
The infestation lasted more than a decade, sparked a massive aerial pesticide campaign and turned Maine's forest industry on its head.
Now, after years of quiet, one of the most destructive forest insects in North America is making a comeback. And Maine landowners have a new plan to avoid another destructive outbreak.
One of the "hotspots" of blossoming budworm populations is about two hours away from the nearest U.S. town down bumpy logging roads.
But the commercial timber stand of spruce and fir trees is within eyesight of Saint-Pamphile, a settlement just on the other side of the Canadian border.
University of Maine at Fort Kent forestry professor Neil Thompson used a handsaw to fell a young fir tree on the edge of the stand. It's the way that budworm monitors like Thompson can count how bad the infestation is.
To a casual observer, the tree looked perfectly healthy. In fact, it's riddled with worms smaller than a grain of rice.
Thompson pointed to telltale signs of budworm — microscopic webbing around the base of tender buds on the tips of the tree limbs and the insect's tiny entrance hole. With a little prodding, a worm crawls out.
Thompson has been using monitor trees like this for years to check on budworm levels. This year the population is so heavy in some places that they will be able to devour entire patches of forest.
"They'll work through the current year of foliage almost immediately and then start back feeding on this old stuff and they could strip this tree," Thompson said, pointing to the fresh buds and existing needles.
Spruce budworms are native to northern forests. And they go through cycles of population explosions and stability. Thompson said evidence of periodic outbreaks goes back about 1,000 years.
All indicators suggest a new outbreak is looming. Fueled by an ongoing infestation in Quebec, budworm levels in northern Maine are on the verge of being considered out of control on several hundred thousand acres.
And forest owners are scrambling to prevent a repeat of the 1970s and 80s.
Back then, Vern Labbe was a state forester, and vividly remembers the outbreak's damage.
"It was really weird as a forester walking through a fully stocked stand and pretty much needing sun tan lotion because there was so much sunlight on the forest floor. Even though it was full of trees, they were all dead," Labbe said.
He recalls the state government bringing in surplus military planes and installing an airfield for an aerial pesticide campaign that sprayed over a million acres of forest a year at its peak.
"You'd fly around, and where it was sprayed, it was green. And where it wasn't sprayed, it was dead," Labbe said. "Pretty much 100% mortality."
The infestation back then changed the face of the North Woods. Timber companies built the first roads deep into the woods to salvage swathes of dead trees. So much of the forest was cut down that it sparked reforms to Maine's forestry laws and a controversial anti-clear cutting referendum. And the pesticide program generated concern for wildlife and habitat.
Nowadays, Labbe runs a Christmas tree farm in Frenchville. And he checks his trees every day for new signs of a budworm problem.
"You know, to have zero damage is probably not realistic," Labbe said. "You're going to have damage. You know, with the insect population we have, it's just a matter of how much damage can you sustain and still have a saleable product?"
A consortium of major timberland owners called the Maine Budworm Response Coalition predict a widespread outbreak would cost thousands of jobs, cripple the forest products industry, increase wildfire risk and hurt tourism and recreation.
But the group, helped with $14 million in federal and state funding, is planning a new aerial spray program this year to head off a serious infestation.
"We believe there is a good solution that will be far superior to what was done in the 1970s, and allow for us to treat the problem at the start, instead of at the peak of panic," said Alex Ingraham, president of Pingree Associates, one of Maine's largest landowners.
The plan is to hit emerging areas of budworm infestation with tebufenozide, a pesticide the U.S. Environmental Protection Agency classifies as "practically nontoxic" to mammals and birds. It works by disrupting caterpillars' molting cycle after they have ingested needles that have been sprayed.
Another option being used is Btk, a bacterial formula sometimes used by organic farmers.
The early intervention strategy is modeled off of a program in New Brunswick. For the last decade, the province has managed to stave off a widespread budworm outbreak by applying the same pesticides to small areas.
And according to the New Brunswick results, companies only need to apply enough pesticide to slightly increase budworms' normal death rate. Birds and other natural predators and pathogens take care of the rest.
Ingraham said the coalition is taking every precaution to apply pesticides safely. Application zones are dialed in using GPS coordinates to avoid sensitive areas such as streams, and spraying will only take place in good wind conditions, according to the coalition.
"We've taken a really serious approach to making sure that we're doing this the right way," Ingraham said.
"We're being very tactical in terms of what areas we're treating, because this is not cheap," he added.
The Maine Forest Service said spraying will take place by mid-June and is closing roads to keep the public out.
It will take up to a year to learn whether treatment is a success. But based on New Brunswick's experience, keeping an outbreak at bay could be a long, expensive process.
