By JEFF BURBRINK
Extension Educator, Purdue Extension Elkhart County

It is not often you can fight a pest with a calendar, but in the case of Hessian fly, that is exactly what wheat growers do in our area.

The Hessian fly is potentially the most serious pest of wheat, barley and rye in our area. The immature maggot of the fly can cause serious damage to the seedlings in the fall by opening wounds on the lower stem, which ooze sap the insect laps up. This weakens the plant and can thin the wheat stand to the point it is often not worth harvesting.

We don’t fight the Hessian fly with insecticides. Rather, the most economic control is to wait until the fly is no longer present to lay eggs. In Elkhart County, the Hessian fly-free date is Sept. 22, and ranges to Oct. 9 in extreme southern Indiana. If you can wait until after that date to plant wheat, the odds are in your favor that the Hessian fly will not bother your fields.

Warmer than normal weather into late summer can extend the Hessian fly beyond its normal fly free date. Hessian fly resistant wheat is available if you plant close to the fly-free date and weather is warmer than typical.

With all the research suggesting that climate change is going to extend our growing season, it will be very interesting to see if our fly-free date changes in a few years.