Multiple corn earworm migration risks are in the forecast the next five days as a rather active weather pattern envelops much of the corn-growing region. No less than two weather systems are set to affect the area into next weekend so southerly wind flow and precipitation may combine to produce more widespread corn earworm migration events in the coming days especially across the central and northern corn-growing regions where crops are at a more susceptible stage to damage.
High risks are in place for this evening into Tuesday morning across northeast Nebraska, southeast South Dakota, southwest Minnesota, and northwest/western Iowa with Moderate risks across central and eastern Nebraska, western Iowa, far northwest Missouri, eastern South Dakota, and southern Minnesota as southerly winds in advance of developing low pressure in the northern Rockies blow north from source regions in Oklahoma and Kansas. At least scattered precipitation should develop in the Plains later today and then spread east into the Moderate/High risk areas by tonight and may serve as insect drop zone regions. The risk areas shift east with the cold front Tuesday night into Wednesday morning and field sites in southeast Minnesota, much of Wisconsin, northwest Illinois, and northeast/eastern Iowa are at the greatest risk for new flights. Moderate risks extend as far east as Lake Michigan and the I-57 corridor in eastern Illinois. Field sites in the eastern Midwest and southern Great Lakes region may also see isolated moth catch increases in lighter southerly wind flow.
Looking ahead to the extended period, the next low pressure system pushes into the Plains and Moderate risks are already in place across portions of South Dakota, Minnesota, Iowa, Missouri, Nebraska, and northeast Kansas by late week and into early next weekend as southerly winds increase. Stay tuned for more updates as the week progresses.