Harvest has been going on great in the upper gulf coast. I've seen and heard about good corn, milo, and cotton yields this year. We've had a few disagreements with the weather and its behavior lately, but otherwise it’s been going well.
I've been seeing whiteflies in some of our later planted cotton. As everything is being defoliated or drying down, these insects are moving into the areas that are still green. Whiteflies reproduce rapidly, they reach reproductive maturity in about 15 days, and the adults live and reproduce for 2-3 weeks. The adults are small white, flying insects, while the nymphs look more like scale insects. The first stage nymph is called a crawler and is the only mobile stage of the immature whitefly. After the nymph molts the first time, it will remain feeding in the same place, and look much like a scale insect.
|Whitefly Adults and Large Nymphs|
Photo from Cotton Bugs
Photo: Kate Harrell
The main concern with these insects is the honeydew they produce. The honeydew can drip into the cotton lint and cause sticky cotton, leading to issues with ginning, staining, and reducing lint quality. Heavy honeydew also fosters the growth of mold, which can cause problems with defoliation as well as staining lint.
If you're only a few days from defoliating and are seeing adults and 20-30 large nymphs per leaf, defoliating soon should be a suitable solution, but keep an eye out for new populations on regrowth.
If you have more than 20-30 adults and large nymphs present, and have eggs and smaller nymphs as well, you may need to consider treatment options. When the populations of these insects get really high, they become much more difficult to control.
Current treatment recommendations include:
- Acetamaprid (intruder or generic) at 2.3 oz/acre
- Sivanto at 10.5- 14 fl oz/acre
- Oberon at 8-16 oz/acre
- Centric at 2.5 oz/acre, but this is the weakest treatment option
As always, give me a call or send me an email or text if you have questions or concerns. Have a good week and good luck harvesting, everyone!
For more information on whiteflies, check out: