Hessian fly can destroy a promising wheat crop. “They are moving west,” Sansone said.

Resistance may be the best control option, but should be combined with other strategies. “Duster and Coronado are resistant and we know resistance is effective on Hessian fly, but we also know that the fly can change.”

Other control options include area-wide planting delay, seed treatments, rotation (helps a little), crop destruction and alternate crops for grazing. “We can’t rely on just one practice,” Sansone said.

The fly is adaptable, too. “It will wait on a one-inch rain and moderate temperatures to emerge in the fall. Delayed emergence, however, often do not build to high numbers.

“A seed treatment may reduce numbers for the first generation, but resistant varieties are still our best option.”

Fall Armyworms

Sansone expects fall armyworms, “will be an issue this year, so farmers should be aware of their planting schemes. If grazing, late planting is not recommended because you can’t delay grazing.”

Control threshold is 10 to 12 larvae per square foot. Wheat may be at risk as long as 210 days after planting.”So what we do today may not be effective tomorrow. It’s important to know yield goals.”

Grasshoppers should be “stopped at the borders,” Sansone said, before they move into the fields. “They usually come in the spring,” and may move into wheat from rangeland and roadside ditches. Populations had begun to decline in August.

Dimlin is the best control option, Sansone said, “but only on grasshoppers without wings.”

rsmith@farmpress.com