There was a significant reduction in potato leaf hopper counts this week. This drop is likely due to timely cutting in the fields we scout, along with frequent heavy rains. When wetter weather, or with days that have heavier morning dews occur, potato leafhoppers can diminish quickly due to the entomopathogenic fungi that can cause the population to collapse. When these conditions occur, and populations of potato leafhoppers drop, there is no need to treat.
Field corn is pushing R3-R4, as the silk is now drying down all the way to the kernel and the kernel is filling out and the ears start into maturity. In soybean, pods are developing all of the way up the plant, and pods are starting to fill. As pod fill begins to occur, it is a critical time to be watching for insects like stink bugs that would be damaging the pods and developing seeds.
This week brought about many sightings of squash vine borer larva. The adult squash vine borer moths were actively flying and lay eggs about a month ago. We are now seeing plants that are declining in health and when inspected further, are oozing frass and have stems that look shredded. When we split the stem of these plants, in nearly every instance, we found at least one, if not several squash vine borer larvae. Unfortunately, there is nothing that can be done to reverse such severe damage.
Flea beetles are feeding on young cabbage and broccoli, and the cabbage worm butterflies are finding their way into these plantings as well. We are starting to see some damage in peppers from the European corn borer and expect the ECB and CEW numbers in the traps to increase in the next week or so.
Small Fruit and Orchards
As apples and peaches are harvested, do not let your guard down on the late season generations of codling moth and oriental fruit moth. This past week was another week of rising codling moth numbers, and consistent oriental fruit moth catches, although the oriental fruit moth numbers have not gone back over threshold.
Grapes are starting to ripen, and as the season progresses, we are still finding consistent trap catches of grape berry moth. Although it may be too late for some varieties, you may still be able to protect later maturing varieties with a treatment for grape berry moth.