As often happens, there is a flurry of activity in early planted cotton. Plant bugs often stack up there first until other cotton starts squaring. I’ve also had reports of more clouded plant bugs in some areas than we’ve been seeing recently.
Pretty much every year I start the season my suggesting the use of Centric and full-labeled rates of imidacloprid prior to flowerin. I’m sticking to the plan for the first spray or two, but once we reach the third week of squaring, I suggest some changes. It has become clear that the neonicotinoids (Centric and imidacloprid) are not providing good control once we start seeing many nymphs in the field. Nymphs often start showing up in meaningful numbers during the third week of bloom. Thus, I suggest a couple of options once a field gets closer to bloom … 1) tank mix 4-6 oz of Diamond with either Centric of imidacloprid, or 2) use Transform at 1.5 oz/acre. A third option could be Vydate. Some will elect to use Acephate/Orthene, but in my opinion we need to save that bullet for later in the season.
The take home point is we really only have a few modes of action and ‘go to’ products for control of immature plant bugs, namely Transform, Diamond, and OP insecticides (really just Acephate or Bidrin). Do your best to mix, match, and rotate these insecticides during bloom.
For more information of sampling, treatment thresholds, and insecticide options see http://guide.utcrops.com/cotton/cotton-insect-guide/plant-bugs/.