Insect Alert For

Corn Earworm

Risk Level:
Low
Affected Area:
Full page
Alert Details

A warmer and more humid weather pattern is predicted across at least a portion of the corn-growing region in the next week as the overall weather pattern shifts into a more zonal flow compared to a dominant northwest flow that has been in place for much of the summer. As a result, more southerly winds and potential precipitation events are predicted this week as is the prospect for at least isolated to scattered corn earworm migration events. The most favored time frame for more widespread corn earworm migration may hold off until the latter half of the week into next weekend, but growers especially west of Lake Michigan should be prepared for the potential of new moth flight in the next week or so. Low risks are in place tonight into tomorrow morning from Kansas, Missouri, and southern Illinois northeast into Iowa, northern Illinois, and Indiana as a weak low pressure area moves through the upper Midwest. Once this system moves through, attention then shifts back to the Plains where southerly winds will be commencing and increasing in strength. Low risks are in place tomorrow night into Wednesday morning across Kansas and Nebraska as well as far western Iowa, with Moderate risks then in place all through the extended portion of the forecast initially across Kansas, Nebraska, northwest Missouri, and western Iowa, but eventually reaching into southeast South Dakota and southern and central Minnesota. By the weekend, Moderate risks extend as far east as western Wisconsin and near the Mississippi River in Iowa and Missouri. Corn earworm remain active in source regions in the mid-south and southern Plains, and crops in that area are not as attractive now as they are further along in their growth. As a result, corn earworm will likely begin moving north when weather conditions allow, and we may see flights especially across the western and central portion of the corn-growing region in the next week.