Western and northern corn rootworms are serious corn pests in Iowa and the Corn Belt. These pests readily adapt to management tactics, especially in continuous corn production. The larvae consume corn roots, thereby reducing nutrient and water uptake, and cause stalk lodging. The adults may also feed on above-ground parts of the plant, including silks and pollen, which may interfere with pollination.

Between May 4 and May 10, 19 trap sites reported a total of 39 black cutworm moths captured in traps (Figure 1). There were no additional significant flights during the week (Figure 2).

Using historical temperature data from the Midwest Regional Climate Center database, Table 1 shows the current projected cutting dates in counties that have had a significant flight. 

Over the last week, there was a lot of field activity across the state—planting, spraying, rotary hoeing, and fertilizer applications. Early planted corn and soybean fields have emerged, but there are concerns about soil crusting impacting emergence and stands. Insect activity is starting to increase, with reports of alfalfa weevil larvae and cutworms.