Jonathan Croft, county agent covering Orangeburg County, reported that “so far the cotton I have looked at this week is looking good and I could find no insect problems. I looked at some earlier planted soybeans that are just starting to bloom and the only insects I picked up when sampling were a few green cloverworms and a couple adult kudzu bugs. I did see a little defoliation in a few areas from some Japanese beetles but it was minimal.”
Rebecca Hellmuth, county agent covering Dorchester and Berkeley Counties, reported seeing some Japanese beetles and snails in soybeans this past week.
Cotton Insects
The recent scattered rains have helped with some issues with spider mites, but places that have missed the rains that had infestations are in worse shape now and need rain over the weekend or control measures next week.
We need to check early blooming cotton for plant bugs and ensure that they are not “knocking off” squares. Although plant bugs have not been a problem in South Carolina cotton, we do have hot spots each year where they should have been addressed.
Check blooms for feeding injury, use a drop/shake cloth to check for adults and nymphs, and monitor square retention. I like to check for the presence or absence of the first position square on the 3rd or 4th node down from the terminal. Check a number of these in each field and calculate a percent retention for each field.
As you know, there will be some physiological shed that we cannot do much about (other than irrigation, proper fertility, etc.), but we want to ensure that a retention problem is not tied to plant bugs. We can control that potential problem, but only if we check for it.
Also, there are pockets of aphids showing up in fields, so look for cupped leaves and honeydew. Finally, bollworm trap numbers are increasing.
Soybean Insects
Aside from infrequent calls about Japanese beetles and armyworms, it is fairly quiet in soybeans, as far as insects go. Japanese beetles can be controlled with a high rate of pyrethroid. Beet armyworms can be controlled with a variety of products. Use thresholds for defoliation when dealing with these pests.
The general defoliation threshold for foliage-feeding pests or pest combinations is 30% leaf-area loss before bloom and 15% thereafter. We should be checking soybeans for defoliating pests and stem-feeding pests right now.
