Southeast Cotton: Be On the Lookout for Plant Bugs

Scott Graham, Extension Entomologist, Auburn University:

“We are hopefully done with planting cotton. We still have some late soybeans to get planted, but cotton should be done. There was a fair amount of rain in southern Alabama from tropical storm Claudette. It was pretty heavy, so some people may be out of the fields for a little while. We saw flooding as far north as Tuscaloosa, so I’d say the south part of the state got hit pretty hard.

“We’ve gotten some pretty nice rains in the last week or so, and we’re doing great with moisture. Now, we just need some sunshine to get it all growing. We’ve got cotton across the state that’s anywhere from 3 to 4 leaf stage or younger to 12 to 14 nodes.

“The biggest thing we’re focused on is plant bugs. They are migrating into the most mature cotton plants right now. Samples from wild hosts have indicated migration will continue for the next 3 to 4 weeks. We’re expecting multiple applications will be needed to handle them all. So, we’re trying to tell everyone if they have cotton that is squaring, you need to be scouting for plant bugs.

“The soybeans are putting on small pods and they are blooming well. We have found some red banded stinkbugs in central Alabama at the research station. Those are neotropical insects from Central and South America, so they don’t winter well. We hoped after such a cold winter, maybe they didn’t make it, but they are starting to build. It could really be an issue for the later-planted beans. Central and south Alabama really need to be scouting for that red banded stinkbug.”

Jeremy Greene, Clemson University Entomologist, Blackville, South Carolina:

“As far as our situation with cotton, I think we’re joining in with a lot of people who just have had too much rain. It is so wet it’s difficult to carry out field operations. We’re going to need to be in the fields soon to take care of weed and pest applications, but there’s just more rain coming.

“I did find quite a few aphids in some hot spots around the fields, and it is about the time for aphids to have our attention. We did find some tarnished plant bugs in the vegetation around the fields and on some of the cotton, so we’re going to keep an eye on that.

“With soybeans, there’s really not much to mention other than grasshoppers are still causing a headache in some spots.”

Brandon Phillips, Phillips Ag Services, LLC, Fitzgerald, Georgia:

“We’ve got cotton anywhere from just planted yesterday (June 21) to starting to bloom. That’s nothing unusual for Georgia, though. We’ve been getting a lot of rain, some spots are getting more than others, and the next few days will just bring more. We were gaining ground with weed control and fertilizers, but this wet weather will put a halt to that.

“The retention is still holding at around 80% or higher. We are still spraying a handful of cotton fields for plant bugs. Some fields are still hitting threshold for plant bugs, but it’s just isolated spots we’re still having to spray.

“A lot of PGR and second rounds of herbicides are going out right now.

“Aphids are starting to build. We are finding more and more pockets of spidermites, even with all the rain. I know a good bit of the places we’re seeing them were treated for thrips, and that just flared up the spidermites.

“With our peanuts, we’re looking at plants that are roughly 20 to 60 days old. A lot of my peanuts are in the 35-to-40-day range. We’re seeing a lot of fungicide applications and weed control going out.

“About 2 weeks ago, we started to pick up tobacco budworms. Because they’re in some of the younger plants, the threshold is lower because there’s just less vine and it doesn’t take them as long to defoliate the whole plant. So, we have been spraying 2 worms to the foot, but have gotten up to 4 worms to the foot in some areas. We’re using Prevathon for those acres. The thing with Prevathon is that we were starting to pick up some lesser cornstalk borers, and this treatment throws them off of their cycle. We may be prolonging their cycle in some ways, so we just have to deal with that too.

“Aspergillus is also still an issue in some areas. The oldest peanuts are getting their second application of fungicide, but that’s about it for peanuts.”

“I’ve got a pretty simple update. Some of the earlier cotton is starting to square, so it’s time to start sweeping for plant bugs. The threshold is 8 bugs per 100 sweeps or less than 80% retention. We rarely get early infestations, but we need to be prepared and pay attention.

“Honestly, we are still struggling just to get the rest of the soybeans planted. We’re kind of hoping for rain; we haven’t gotten enough of it to make us struggle like other places. Not much to say other than that.”

Phillip Roberts, Extension Entomologist, Tifton, Georgia:

“We are getting much-needed rain today (June 22). The crop is off to a pretty decent start, but this rain helps.

“In terms of insects, we need to make sure all squaring cotton is being scouted for plant bugs. There are two things to do with scouting. The first is to monitor square retention. We need to be retaining 80% or more. If we have 80% retention when we enter bloom, then we still have maximum yield potential. We can also monitor by using sweep nets. We just need to be sure we are scouting all fields that are squaring and that we are prepared to react. I would also say we shouldn’t spray unless it’s necessary so we can preserve some of the beneficial insects.

“Aphids are slow to develop this year, and I’m not sure why. It may be the weather conditions we’ve had, I’m not sure. We did see an increase in aphids this week, but it’s still lower than normal. I would say it’s a judgement call if you should treat or not based on the stress on the plant from the aphids. I will say when we do research trials with UGA, we cannot show consistent yield response to control aphids in cotton.”