We recently published a holistic article to plan for tarnished plant bug in 2023. Since then, we have received a lot of questions about what to use at this point in the season as folks are making passes over the field with herbicides and growth regulators.
First off, follow our threshold recommendations. Even if you can piggy back an insecticide, spraying at sub-threshold levels is throwing money down the drain. Prior to bloom, this threshold is >80% square retention AND eight plant bugs in 100 sweeps. In most situations, yield will not be gained retaining squares above the 80% level. Be sure to switch to using a drop cloth (for these reasons) when cotton blooms and only spray if levels reach 2-3 plant bugs per drop cloth sample. Keep in mind that all cotton, including ThryvOn, should be scouted and treated for tarnished plant bugs if the threshold is exceeded.
At this point in the season (July), growers should use Transform at 2 - 2.25oz, following our regional insecticide recommendations that change across the growing season. Transform will preserve beneficial insects that can provide bioresidual, to hold back more plants bugs, stink bugs, bollworms, spider mites and aphids. We have already seen spider mites at treatable levels across the Coastal Plain. Spider mites are worse in hot and dry conditions, but are also flared by acephate (Orthene). Try not to use this insecticide until later in the season. Do not use Diamond until nymphs are present and multiple sprays are expected.
Finally, neonicotinoic (Admire Pro, Belay, Centric) efficacy tends to wane throughout the season. Sprayed alone, these insecticides are generally less effective than Transform and have inconsistent efficacy. They can be used as tank mix partners, however.