Tarnished plant bug numbers appear to be low thus far in 2026 and clouded plant bugs are non-existent. Crop age and what’s neighboring your cotton play a large part of how intense plant bug pressure is over time. That being said, keeping an eye on square retention is the best gauge to determine how well your insecticides are performing. Most I’ve talked to haven’t applied Diamond yet or have it queued up for their next application. Diamond shines when you catch early plant bug hatches often after large adult migrations during late squaring and we see a good ROI with Diamond around that 1st week of bloom timing.
Going into bloom, I don’t think neonics have a fit in any scenario. Every time we test a neonic sprayed after bloom its often one of, if not, the worst treatments in the test. Once you see a flower migrate to the Transform, Acephate, Bidrin, Vertento treatments. Pyrethroids can be added in with OP’s to help increase control and acephate + pyrethroid can catch a few bollworms in the top of the canopy later in the season (although our 3 gene cottons have been doing a great job of controlling bollworms in previous years). Diamond should rotated around in the bloom mix also. Overlapping Diamond residual, usually spaced out every other shot, can help reinforce control of nymphs. I don’t like Diamond fb Diamond in succession. Diamond’s effects may take 7 to even 10 days to notice and sequential shots may not take full advantage of the residual it provides, but that’s situation dependent.
I mentioned in a previous blog post about saving Vertento until bloom. The Midsouth Entomology Working Group (MSEWG) agrees that Vertento’s best fit is bloom to peak bloom. I personally like Vertento during peak bloom (roughly 3rd week) to maximize its activity spectrum (plant bugs, stink bugs and spider mites) and justify its cost. One note of caution, Vertento is not a spray it and forget the crop for the rest of the season application. Keep scouting no matter what you use. The deeper in bloom you spray Vertento the higher likelihood you’ll finish the season out with insect applications. First bloom applications will probably need to be followed up with something on the tail end. Also, make sure you use a quality surfactant with Vertento , our data indicates a COC, MSO performs better than NIS. Premium organosilicone surfactants work well too. I haven’t experienced any differences in control when surfactants are used at 0.25% v/v or 1.0%v/v.
Thryvon performance is on par with what we’re accustomed to seeing. Square retention is often better in Thryvon and plant bug numbers, especially nymphs, are lower. Insecticides seem to perform better in Thryvon for a couple of reasons. Less insects are typically easier to control, plant bug population growth is slower and we think the nymphs don’t settle in bracts/blooms like they do in non-Thryvon. Nymphs are constantly moving in Thryvon and the more they move, the higher likelihood they’ll encounter an insecticide. Final note, my Phd student has data that shows Thryvon efficacy on clouded plant bugs are very similar to tarnished. We see increased square retention and slower population growth from clouds like we do tarnished.
