Corn earworm (CEW) showed a moderate surge of activity during this past week, from 19-22 July when our pheromone trap in Columbus caught 49 moths in a 4-day period. This follows a few weeks of low CEW moth catch, after high CEW moth catch in late June. A pheromone trap near Fremont caught 74 CEW moths this past week. The corn earworm moths will be laying their eggs on silks of sweet corn. Sweet corn can be protected from corn earworm infestation by insecticide sprays during silking. When the number of CEW moths caught in traps is moderate (1 to 13 moths per day, or 7 to 90 moths per week), then sprays should be applied every 4 days if the daily maximum temperatures is below 80 degrees F, or every 3 days if the daily maximum temperatures is above 80 degrees F. More information about CEW, traps, and trap-based spray schedules is available using this link: http://u.osu.edu/pestmanagement/crops/swcorn/ .
The typical insect pests of mid-summer are currently being found on Ohio farms. Squash bug eggs and young nymphs are being found in squash and pumpkin fields. Cucumber beetles, both striped and spotted, are feeding in flowers of squash and melons. Squash vine borer is past its peak in terms of the number of adult moths caught in pheromone traps, which peaked in early July. The tobacco hornworm is feeding on tomatoes in the field and in high tunnels. Imported cabbageworm is feeding on cabbage and other Brassica crops. Colorado potato beetle adults are on eggplant and potato. Blister beetles are reported on potato. Sap beetles and western corn rootworm beetles are being seen on sweet corn. Japanese beetles are found on sweet corn, asparagus ferns, and various fruit crops, but they seem to be less numerous now than several weeks ago when huge numbers were seen.
The second generation of the European corn borer has not yet been detected, but it should start within the next week or two, and will be important in peppers and sweet corn.
An encouraging note is that many beneficial insects are also active in vegetable crops. Recent sightings include many Orius predatory bugs and the pink lady beetle in sweet corn, lady beetle larvae, lacewing larvae, the spined soldier bug, and damsel bugs in a variety of crops.
-Celeste Welty, Extension Entomologist