Monitoring for Common Stalk Borer
With hot temperatures occurring this past week, a lot of degree days have accumulated. However, common stalk borer activity likely remains limited to grass and weeds bordering fields. Although the common stalk borer is considered a minor pest, it can cause issues in the border rows of fields. Common stalk borers are an early season pest that initially feeds on corn leaves. As they grow, they move to the whorl of the plant and bore into the growing point. This activity can result in dead heart and subsequent plant death.
With hot temperatures occurring this past week, a lot of degree days have accumulated. However, common stalk borer activity likely remains limited to grass and weeds bordering fields. Although the common stalk borer is considered a minor pest, it can cause issues in the border rows of fields. Common stalk borers are an early season pest that initially feeds on corn leaves. As they grow, they move to the whorl of the plant and bore into the growing point. This activity can result in dead heart and subsequent plant death.
Predicting common stalk borer migration into corn fields with degree days
The hatching and movement of common stalk borer caterpillars can be estimated by using degree days with a developmental threshold of 41°F. Common stalk borer eggs typically begin to hatch at 575 degree days. The caterpillars finish hatching and begin development on weeds and grasses at 750 degree days. At 1300 degree days, 10% of the caterpillars will begin moving to corn. At this point corn should begin to be scouted. At 1400 degree days, 50% of the caterpillars will or have moved into corn.