Missouri farmers fighting infestations of armyworms

NEVADA, Mo. -- After coping with a severe spring freeze and days of torrential rain, farmers in parts of southern and western Missouri are confronting yet another enemy: armyworms.

No one can say yet if voracious caterpillars will cause destruction of grasses and wheat on the scale of infestations that hit Missouri in 2001 and, to a lesser extent, again in 2004.

But experts are counseling farmers against taking chances. As fields dry, they advise cutting fescue as soon as possible to beat the armyworms to the seed and to get better quality hay.

"We seldom get this done because of rain or being too busy in other fields, and get around to cutting fescue later," said Pat Miller, University of Missouri Extension agronomist in Nevada.

Jay Chism, an Extension agronomist in the far southwestern town of Lamar, said he has received many calls from farmers asking about armyworms in grass and wheat fields.

Fields should be checked late in the day or at night. Spraying is economically justified with an average of four half-grown or larger armyworms per square foot, he said.

Armyworms got their name because they seem to march across fields in large formations, leaving little in their aftermath. They can strip a field in a day.

"They eat everything, they'll eat it right down to the ground," said Lloyd Darter, an aerial crop duster whose service has been in demand this spring in southwest Missouri.

Near Buffalo in Dallas County, farmer Butch Rankin recently marked out the fields where he planned to attack.

"I'm going to aerial-spray this, and the other alternative is to mow with a haybine to stop the source of feed, and they'll starve to death," Rankin said.

The costs of spraying have to be weighed against the loss of a hay crop.

"At, say, $40 a bale, there's $8,000," Rankin said of one field. "If they destroy it, you don't get it."

Missouri's worst infestation of the past decade occurred in 2001, causing millions of dollars of losses to farmers throughout the southern half of the state. Extension agents reported farmers losing as many as 200 acres in a weekend to armyworms.

A serious and more unusual infestation also struck in 2004, when armyworms ate their way across hayfields in parts of northern Missouri, where they are rarely found.