Armyworms attacking pastures, wheat in Texas

Linda Stewart Ball, Associated Press Yahoo News 17 Oct 08;

DALLAS – Texas farmers are once again battling armyworms and the voracious creatures are attacking fields and pastures in formidable numbers.

"There are probably more armyworms this year than in previous years," Allen Knutson, an entomologist with the Texas A&M University System, said Thursday.

The armyworm, which is actually the caterpillar or larva of the night-flying moth, do the most damage in the fall, when they're at their peak, nearly fully grown at about an inch-and-a-half long. They'll chomp on any plant, but prefer grasses, especially the lush and well-fertilized hay meadows and pastures in North, East and Central Texas.

"Unless the farmer is looking very closely, he won't realize he has a problem" until it's too late, Knutson said. "Almost overnight a field can be consumed by armyworms. A farmer drives by and says 'Oh my goodness, I've lost my crop.'"

The armyworm gets its name from its method of operation. The larvae occur in large army-like numbers and when they eat all the food in one area they "march" en masse, across roads and fence lines, to the next field for feeding, unseen in the darkness and cool of the night.

"When small, they eat very little," Knutson said. "But after 10 days to two weeks, they turn into eating machines."

He said armyworms consume about 80 percent of all the food they will eat in the last two to three days of their 30-day life cycle as a caterpillar.

The cool temperatures in the fall and generally higher rainfall are favorable for armyworm outbreaks.

Brian Betts, who farms about 1,000 acres in East Texas for his beef cattle, has already been plagued with two generations of armyworms this year and fears a third infestation.

"We're checking every day because we've got oats and wheat planted," Betts said. "If they get in there, they'll destroy it. ... Catching them early is the key."

Pesticides are an effective counterattack, extension agents say, though it's possible to spend more on chemical controls then the pasture or harvest of hay is worth.

Betts said if he loses his current crop he'll have to depend on grain and hay to get his cattle through the winter.

The moths hibernate or winter in South Texas, then fly north in the spring and summer by the millions, looking for the perfect field to lay their eggs.

"One moth can lay 2,000 eggs," said Kenny Rollins, an extension agent in northeast Texas, adding that the armyworms showed up earlier than in past years. "Every year, Mother Nature throws us a curve. When it's wet, we have disease and fungal problems. When it's dry, grasshopper problems."

This year, there was enough moisture early in the season to draw more armyworms, Rollins said. They'll devour winter pastures until the first freeze.