I caught my first earworm (Figure 1) moth in a pheromone trap last week. Earworms are very polyphagous, meaning they will eat lots of different plants. I suspect that any females that are flying are laying their eggs on wild plants of some sort and not on the seedling stage sweet corn or dent corn that is present in fields around the state. If you are one of the aggressive growers who grows sweet corn in the greenhouse and transplants it to the field to get that early market, your plants (unless they are covered by row cover) may be subject to earworm egg laying and feeding. This generation of larvae will be long gone before ears begin to form, so your only concern will be the foliar feeding damage and not ear infestation.
Corn earworm. (Photo by Dan Egel)