MANSFIELD - Dairy farmer Terry Wilson said his corn, hay and oat crops were coming up like they should until a week ago when he noticed one field full of young corn that looked like it was only half there. Closer examination revealed it had been eaten down to the ground by pseudaleta unipuncta, or armyworms.
Investigation of the rest of his fields in Richmond Township - 28 acres of oats, 240 acres of hay and 40 acres of corn - showed varying degrees of damage, Wilson said.
"I probably lost $50,000 in the last week," he said.
CHERYL R. CLARKE/Sun-Gazette
Tioga County dairy farmer Terry Wilson looks at a 5-acre field that was filled with young corn until armyworms ate it down to the ground last week.
Farmers throughout the county have told Wilson they, too, are seeing damage from the pests, which turn into moths once they are done feeding on "anything green" except weeds.
And the damage isn't limited to Tioga County. According to Craig Williams, Tioga County's horticultural educator for the Penn State Cooperative Extension, the voracious worms are "everywhere."
Counties to the west and southeast are suffering with the pests as well, Williams said, adding that he has heard of infestations in Clinton, Potter, Bradford, Lehigh and Lancaster counties.
So far, Lycoming County Cooperative Extension agent Carol Loveland said she has not had any calls about the worms.
The infestation this year could have come from the mild winter, but also comes from ground that has lain fallow where the moths lay their eggs, and then is tilled and planted with crops, Williams said.
"They have some natural predators in birds. But you have such a big infestation right now, the birds can't take care of them all," he said.
Wilson said he never has seen this kind of infestation during a lifetime of farming, and that of his father and grandfather before him.
Spraying with a powerful insecticide that, according to Wilson, "you have to have a license to buy," is the only answer. That means hiring someone to do it - at $20 to $30 per acre.
With a constant battle against all kinds of weather in the past two years, first a wet spring last year, followed by a dry summer, then a wet, stormy fall and no winter to speak of, pests such as armyworms are just the latest thing to come against dairy and grain farmers that have seen their costs triple in the same time frame.
"Most of the agronomy agents in the state are talking about it. They eat anything that is green, until they are about an inch and a half long, then they change to a pupa stage, then into moths, and they lay eggs again so we could have a re-infestation in late July," Williams said.
Mowing any standing hay should be done before spraying, he said, but if there is a corn field right next to a hay field, farmers should spray it because "they will just walk right over to it."
"They have to walk from one field to the next, not fly," he said.
Wilson said he mowed a hay field next to the road Monday and once he finished, the worms could be seen walking across the road to the fields on the other side, making the road look "black with them."
What that leaves for farmers is not just the loss of a crop, because they will have to spray and then hope whatever might have been left by the critters comes back.
If not, they will have to replant and hope there isn't an early frost before their crops come to maturity.
Hay that is destroyed can be cut but according to Wilson, the cows won't eat it when it is just stem, so it is only good for mulch, reducing the value from $80 per ton to $20.
Farmers aren't the only ones potentially harmed by the pests, Williams said.
"If they get into swimming pools they can clog swimming pool filters, and they will eat your yard, gardens, anything but weeds," he added.
Insecticides containing synthetic pyrethroids are the most effective against the worms, and can be purchased in some lawn and garden stores, but others that leave the more beneficial insects alone also are available, Clinton County horticulture educator Tom Butzler said.
"They are in such large numbers it is difficult to control them," he added.
For more information on armyworms, visit extension.psu.edu/field-crop-news/archives/2012.