PITTSFIELD – The worst plague of army worms in memory is crawling its way across the state, devouring hay, barley and oat fields, lawns, backyard gardens and cornfields. State officials are saying the infestation is nearing disaster proportions.

“We’ve had them here in Maine off and on for 30 years,” Walt Whitcomb, a dairy farmer in Belfast and chairman of the Maine Dairy Industry, said Tuesday. “But not like this. This infestation is far more widespread.

“When they start moving en masse for food, it looks like the whole road is moving.”

In less than three days, an army of the worms can eat a 10-acre field bare. They can devour a front lawn in an afternoon.

Tom Davis, a Penobscot County commissioner and farmer, said Tuesday that the worms have eaten 300 acres of his grain grasses in Kenduskeag.

“I have farmed all my life and I’ve never seen it this bad. They’re all the way in Aroostook County, and that’s a long way to march,” he wryly joked.

Although the invasion appears to be at its worst across central Maine, pockets of worms have appeared as far north as Presque Isle.

“We have been receiving calls from farmers all over the state,” said Jon Olson of the Maine Farm Bureau.

A Canton farmer, Ralph Sayer, said the worms were so thick at his farm that he could hear them crossing the rock bed of nearby railroad tracks.

“It sounded like the crunch, crunch, crunch of peanut shells. They were so thick, I didn’t want to get off my tractor,” said Sayer. “When they get through eating, all that’s left are the dandelions.”

Sayer said he has lost nearly his entire second cutting of hay. “I cut a 28-acre field this week and got 160 bales,” he said. “Usually, that field would yield up to 1,500 bales.”

The worms, which have decimated farms from Texas to Minnesota to North Carolina and last year threatened the food supply in five African countries, are the larval stage of the moth Pseudaletia unipuncta. The army worm is a hairless caterpillar with a yellow Y on its head, black bands, and three yellow stripes down its back. If a plant is lush and succulent, the worm will defoliate it and eat it to the ground. The worms travel in large groups, “marching” together through fields.

The larval stage lasts for 10 days to two weeks; then the army worms turn into moths and fly away. Until then, Maine farmers are struggling to save their crops.

James Dill of the University of Maine Pest Management Department said Tuesday that the worms started hatching in Maine in mid-June.

“This was quite unusual,” he said, “because army worm infestations usually follow a wet spring. This year, we believe that because we had such a good snow cover followed by a warm spring, the eggs wintered over.”

Dill said the infestation is considered major and will have dire financial consequences for Maine farmers. “I’m sure in some areas crop insurance will kick in. There are some definite disaster areas in the state,” he said.

Whitcomb said the worms have arrived at precisely the time during Maine’s growing season when the plants are lush. “This takes what would have been a great [crop] year and turns it into a very bad year. The crop we are losing is of very high value,” said the farmer.

Ned Porter, deputy commissioner of the Maine Department of Agriculture, said he is referring questions to the experts at the UM Cooperative Extension, as well as monitoring the financial impact of the agricultural losses caused by the army worm. It is unclear at this point just how large that impact will be, but Porter said the department would continue to tally the losses and would request disaster assistance if appropriate.

Meanwhile, said Dill, farmers should be keeping an eye out for the second hatching.

“There are millions of worms out there, and once they pupate into moths, each female moth can lay up to 500 eggs. We don’t usually have a second generational outbreak,” said Dill. He suggested, however, that farmers begin “keeping an eye out for the second hatching in about three weeks.”

Whitcomb said Maine farmers are out in their fields, checking daily for the worms. “If they find them, they are spraying either pesticides or liquid manure, which will kill them,” he said. “I know one farmer in Albion who said he has spent four straight days on his sprayer.”

Other farmers are harvesting their hay, even though it is not fully grown, in an attempt to save it from the voracious worms.