By Carroll Smith
This month, Cotton Farming is focusing on familiar insect pests that likely will be back again this year. In the cover article, several consultants discuss what cotton insect pests they expect to see in their respective cotton-growing regions. To supplement the Mid-South report, Cotton Farming has gathered timely comments on May 30 from Extension entomologists in Mississippi, Louisiana and Arkansas. Following are their
thoughts on this subject:
Dr. Angus Catchot
Mississippi State University
Right now in Mississippi we are experiencing very heavy thrips pressure throughout the Delta and in thecotton that has come up in the hills. Much of the cotton is not even to thethrips stage yet because this crop is extremely late. But the cotton that is up and has a leaf on it has a lot of thrips.
Quite a few overtreatments are being made. With this really late crop, people are trying to push it. We don’t want to delay the crop any more since we are already three weeks later than normal.
Consequences of Thrips Pressure
Many applications are being made a little sooner than they would in a normal planted year because we know that some of this thrips pressure will definitely hold the crop back on thetail end. And we don’t have a lot of time for that this year.
Another consequence of thrips injury is that it can act like a late planting date. When thrips eat the plants up, the plants may be held back sometimes as much as two weeks, depending on the amount of injury. Again, this exposes you further to late-season insectproblems.
Dr. David Kerns
In Louisiana, we actually had a decent planting window so we pretty much got our cotton planted. However, the window closed quickly, and some of the cotton had stand issues. The stands weren’t really bad enough to justify replanting, but were getting down on the lower end of what is acceptable. Our cotton is behind about a week or more primarily because of the cool temperatures.
Right now we are seeing spider mites in a few fields, and I already saw a number of applications go out targeting those, which is not entirely unusual. In cool, damp conditions, we tend to have a lot more weeds, which have a good reservoir of mites in them. I think that is where they are coming from. I also believe we are getting some out of the tree lines, too.
Last year we had quite a few western flower thrips, but so far this year, 90 to 99 percent of what I am seeing are tobacco thrips, which is good. If you are going to have thrips, tobacco thrips are not as difficult to control.
This year we also are picking up a lot of bollworms in corn – whorl feeders. We hardly saw those at all last year. Now, whether that is going to translate to a bad bollworm year, I don’t know.
Lastly, with the damp and cool conditions, the clovers bloomed really well and drew a lot of tarnished plant bugs. There are plenty of other weed hosts, too, but I swept a lot ofclover this spring, and it was loaded up. There is a pretty good potential for a heavy plant bug population this year.
Plant bugs feed in the seed heads of clover, particularly red clover. We pick up a lot in the white clover, but if you get in a big patch of red clover, it’s just loaded with them.
Dr. Gus Lorenz
University of Arkansas
In Arkansas, right off the block we are seeing fields where thrips are getting started pretty early even where we have seed treatments. The seed treatments may not seem to be performing as well as we would like, and a lot of that has to do with the fact that the seed sat in the ground a long time before it came up. The seeds have struggled to get out of the ground, so we have a lot of cotton that is struggling right now. That’s when thrips have a tendency to jump on you.
While pulling thrips samples in our plots, we are also seeing some aphids out there. That could be a message to us that aphid pressure may be a little high this year. It’s awfully early for us to be picking up aphids at those levels at this time in the season. We will be watching this situation because it’s already been three or four weeks since cotton was planted. The neonicotinoid seed treatments are going to start running out of gas, so we need to be on the lookout for that.
Tarnished Plant Bugs
Obviously, we have a late crop. We have to wonder how bad tarnished plant bugs could be this year because we do have a little later crop. If corn is tassling and silking at the time we start putting fruit on our cotton, tarnished plant bug numbers could be pretty high this year. I don’t want to be a predictor, but it certainly seems like we are getting set up for a plant bug year. We’ll just have to see how things evolve from here.
Any time we get into late crops like we have this year, the potential for insect issues becomes more and more predominant. That includes bollworms and everything else. In all of our crops, we are set up for insect issues related to late planting. We escaped this last year. We had a great spring last year, got an early start and avoided a lot of insect issues out there, but this year is different. Insects are probably going to be more predominant.
Mites are already out there because we picked some up in our thrips samples. As we transition into the dry period, that’s going to become a concern. We are set up for all kinds of insect issues this year so it’s important to scout closely because pest problems can pop up all of a sudden. Being thorough with your scouting is going to be really important.
Cotton Farming would like to thank Drs. Catchot, Kerns and Lorenz for sharing their observations regarding what cotton farmers mayexpect to see as far as insect pests in Mid-South crop this season.