Gypsy moths stalk the North Shore

Gypsy moth trap
A gypsy moth trap is hung on a tree, near the Gunflint Trail, north of Grand Marais. Traps are placed in a grid, spaced less than a mile apart. The traps are best placed in a breezy area, along a forest edge. A chemical pheromone in the trap can attract male gypsy moths from up to a mile away.
MPR Photo/Bob Kelleher

Bob Kangas used to be a game warden. Now he's a trapper, and he's after some tiny wildlife.

Bob Kangas
Bob Kangas checks a gypsy moth trap north of Grand Marais.
MPR Photo/Bob Kelleher

Kangas has steered his four wheel drive pickup onto a narrow, overgrown forest road - and up a steep and rocky slope - looking for the just the right tree for his trap.

"The trap consists of a cardboard container that has what they call tangle foot on the inside of it." Kangas says. "And the tangle foot is like a flypaper sticky stuff, so when the moths fly in there they get stuck on it."

The moths are gypsy moths, and when in the caterpillar stage, they're notorious for their numbers and their appetites. The caterpillars can eat every leaf off a tree, and strip clean a wide tract of forest.

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Weak trees can die. And an infestation comes with a substantial "ick" factor. Caterpillars swing by the thousands from long webs. Their droppings fall to the ground like rain.

Gypsy Moth
A trapped gypsy moth is displayed at a public meeting in Grand Marais, on the upcoming battle against North Shore gypsy moths.
MPR Photo/Bob Kelleher

Gypsy moths have been slowly approaching Minnesota from the East Coast for a hundred years. Kangas says, until last year, the number of moths weren't a huge concern.

"It was nothing compared to last year," says Kangas. "Last year it was well over 1,000 moths in this area, and the year before I forget the number but it wasn't a hundred I don't think."

These aren't Minnesota's first gypsy moths. Smaller outbreaks have turned up including near the Twin Cities, and two years ago near the town of Tower. Kimberly Thielen-Cremers heads the gypsy moth program for the Minnesota Department of Agriculture.

"What we're seeing right now are isolated pockets, kind of like a forest fire. We're seeing these spot locations, isolated populations, kind of out in advance of the front," says Thielen-Cremers. "What we're trying to do is stomp out those isolated populations before they have a chance to coalesce."

The moths are stomped out two ways. A couple of weeks ago foresters sprayed a pesticide on the Grand Portage Indian Reservation. That's where they found the most dense concentrations of moths last year.

Placing a trap in Grand Marais
Bob Kangas places a gypsy moth trap on a tree, in front of a Grand Marais apartment complex. He follows a map grid that includes city locations, as well as trap sites that are deep in the forest, well beyond established roads or paths.
MPR Photo/Bob Kelleher

In a few weeks, airplanes will rain tiny plastic flakes on up to 130,000 acres from Grand Marais to Schroeder some 30 miles away. The little green flakes are loaded with moth pheromone - intended to confuse male moths, and keep them from finding females.

Next, officials hope to keep new eggs masses from coming in. Gypsy moths are famed for their ability to travel - with people. Egg masses can move on trucks, trailers or boats. Or they could be coming in on firewood.

Already, Michigan and Wisconsin have firewood restrictions to stop another forest pest that kills ash trees. Thielen-Cremers says firewood is a great way to move gypsy moth eggs too.

"Firewood is a huge 'impacter' - a huge movement of gypsy moth, and other pests," says Thielen-Cremers. "We're seeing that with emerald ash borer and other insects being moved with firewood. Folks think they're doing somebody a favor when they bring their firewood in and they leave it at a campsite, that the next person doesn't have to pay the $3 or $5 for a bundle of firewood, when in fact they're probably doing more damage to the environment by leaving that wood behind."

Kimberly Thielen-Cremers
Kimberly Thielen-Cremers is the gypsy moth program coordinator for the Minnesota Department of Agriculture.
MPR Photo/Bob Kelleher

So far, there are no restrictions on moving firewood around Minnesota. But officials recommend you don't - whether you live in an infested area or not, according to Minnesota Department of Agriculture spokesman Mike Schommer.

"The big thing is don't bring in firewood from where, from your residence if you're going to a different part of the state, buy the firewood once you get there," says Schommer. "Use it all up. Don't take it home with you."

A state task force is now talking about what to do about firewood. Its recommendations - including potential restrictions on moving some wood - could be in place in another year, not just for gypsy moths but other forest pests as well.

And still, officials say they can't hold the gypsy moth at bay forever. At best, Thielen-Cremers says, Minnesota is maybe five to 10 years away from having a permanent gypsy moth population. Another five or 10 years after that, and people will see their effects, in bare trees in the middle of summer.