Originally posted in the VegNet Newsletter, June 23,2018
As the earliest sweet corn plantings are in or approaching the silking stage, be aware that the corn earworm is present at some locations, as detected by pheromone traps that attract the adult moth. Although the number of moths beings caught is low, these small populations can concentrate on the few patches of early sweet corn, and can cause significant damage. Once the large acreage of field corn begins to silk, then the pest population will be spread out over a much larger area and the pest pressure on sweet corn is usually reduced. Trap counts can be found at this website: http://u.osu.edu/pestmanagement/
Some vegetable growers are concerned about thrips invading their crops if strawberries are nearby because some strawberry farms had severe problems with thrips this year. The thrips that infests strawberries is the eastern flower thrips. This thrips does not show up every year in the midwestern USA but can arrive in large numbers in the spring by being blown in on weather fronts that move from the southern USA. Thrips are known as an occasional pest of tomatoes. They are not known to damage bell peppers or sweet corn or melons, but there are reports of them currently being found in flowers of these crops.
Pests that seem to be currently showing typical activity are squash vine borer, which has been active for the past 3 weeks, and which will be infesting squash, pumpkins, and gourds. Black cutworm moths have been detected at higher than usual density during the past 2 weeks when the weather has been hot, and can be a concern in potato, radish, and other root crops. Populations of the variegated cutworm have also increased greatly in the past week. The adult of true armyworm has been detected at much higher than usual numbers in traps for the past 2 weeks but no reports have been received of it damaging sweet corn or other grassy crops. Japanese beetlesare being seen in sweet corn and in various shade trees during the past week.