Rick Minzenmayer has something new to worry about. In early April, the Texas Cooperative Extension entomologist for Runnels and Tom Green counties was asked to check a wheat field just north of Rowena that wasn't doing well.

“It looked bad, and the farmers couldn't figure out what was wrong with it,” said Minzenmayer. “I went out there and after looking closely determined the damage was the result of Hessian fly.

“They were everywhere. Plants are lodging in the field and many plants were actually dying. It looked terrible.”

The entomologist said this outbreak marks the first time the pest has been found in Runnels County. He said once a field has been hit hard, the crop is lost. He said the outbreak was likely caused by an introduction of wheat straw or harvest equipment that harbored the insects.

“The flies kind of jumped over into our area, so apparently they were brought in last year,” said Minzenmayer. “They established last fall and we're finding them now.

“This means this area will now have to start planting resistant wheat varieties. Producers will also have to plant later in the affected area, probably no sooner than November. Traditional September planting of wheat for early grazing is out in the affected area unless producers plant resistant varieties.

“There's only a few wheat varieties that are actually resistant. Unfortunately, they are not as good for grazing as the beardless wheats most of our producers plant for grazing.

“Beardless wheats are very susceptible to the Hessian fly.

“TAM-400 and some of the Pioneer wheat varieties are resistant. Coronado has some resistance. Other than these few, most of the wheat planted in our region is susceptible.

Minzenmayer is not sure how much wheat has been hit by the tiny insects yet. He said six fields in close proximity to the affected field were all infested. The pocket of trouble probably totals 250 to 300 acres.

Currently, the crop insurance adjusters are looking at the damage and releasing those fields so they can be plowed under. The stubble must be buried four to six inches deep to reduce the fly's survivability

Burying the stubble prevents the adult from emerging. The fields must be destroyed as quickly as possible, so grazing them out is not an option.

“We want to alert producers, especially those hiring custom harvesters, to make sure those combines and other equipment are clean prior to coming into their fields,” he said. “If that machinery has been working south and east of here, local producers need to insist that the equipment be thoroughly cleaned before it is even brought to our area.

“These flies are very small and have difficulty traveling on their own more than one mile. They only live about three days in the adult stage, so their natural movement is extremely slow,” he said.

“They are obviously getting some unintentional help somewhere”

s-byrns@tamu.edu