Insect Alert For

Corn Earworm

Risk Level:
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Alert Details

A heat dome is predicted to envelop a good portion of the corn-growing region especially west of the Great Lakes later this week and likely into at least the first part of the weekend in some fields. The storm track will focus further to the north during this time with southerly winds present to the south. Corn earworm migration probabilities are in the forecast on a daily basis through the period, but stay in the Low category initially due to the largely unfavorable southern Plains source region for the southerly winds. Low risks are found mainly west of a line from east of Springfield, Missouri to Wausau, Wisconsin and as far north as the I-94 corridor in Minnesota and North Dakota. Essentially the same risk area is found in the forecast tomorrow night into Thursday morning, but it also extends further east to near Lake Michigan and into the I-57 corridor in Illinois, as well. As we move into late week and especially next weekend, a cold front will eventually push southeast through the corn-growing region and end the heat, but as it does so, it will also increase corn earworm migration risks due to a more favorable southerly wind source region across the mid-south and increased precipitation chances. Moderate risks are in the forecast from Nebraska east into western Illinois and south into northern Missouri and as far north as central Minnesota and Wisconsin by Friday night into Saturday. The Moderate risk extends from roughly I-35 in central Iowa east into southwest lower Michigan and northern Indiana Saturday night into Sunday morning. Low risks push east into southern Ontario, Canada and Ohio during this time, as well. Growers should be on the alert for new or additional corn earworm moth flights in the next week by monitoring traps and taking appropriate action where needed.