Corn earworm migration is predicted on an isolated basis for the next five days as a persistent area of low pressure remains across the Plains states and high pressure drifts southeast from the Great Lakes into the eastern seaboard. In between the two pressure centers, southerly winds may result in isolated moth flights northward from source regions in Texas initially but eventually further east into Arkansas and Louisiana. Low risks are in the forecast tonight into Saturday morning across portions of Kansas and Nebraska, then further east and north into southern South Dakota, Minnesota, the western two-thirds of Iowa, and Missouri by Saturday night into Sunday morning. By late in the holiday weekend and early next week, the risk spreads as far east as the southern Great Lakes region and eastern Midwest as south to southwest winds advance further east. Growers in the Low risk area should especially monitor host plants for signs of new corn earworm moths by next week.
No risk of western bean cutworm development or migration is predicted in the next five days.
Corn rootworm hatch is expected to begin late in the Memorial Day weekend especially in fields located from central Illinois eastward into portions of western and central Indiana. Accumulated soil temperature growing degree days across this region should be high enough to allow initial corn rootworm hatch by Sunday or Monday May 26-27. Growers in these areas should monitor their fields for signs of corn rootworm hatch in the next week.