By Clint Thompson
Late season plant bugs have become more of a nuisance for Georgia cotton growers. It may be attributed to increased resistance in certain insecticides, says Phillip Roberts, University of Georgia Extension cotton entomologist.
He discussed plant bugs during the annual Georgia Cotton Commission meeting in January. Roberts said there were very high plant bug populations last year, nymphs and adults, in mid-late bloom cotton in some areas.
“Plant bugs are just something that have required more and more management the last few years. We struggled in a few parts in Georgia, particularly on the western side of the state. Yes, some things have changed, and we will have to approach it a little differently,” Roberts said.
“Regardless of what pyrethroid it was, it does appear we have resistant plant bugs; plant bugs we cannot control with these pyrethroids. That’s most likely why we had some problem areas last year. We just missed them. As we go into this year, we know what to expect so we can make better decisions.”
Producers should be mindful that bifenthrin is no longer providing acceptable control of tarnished plant bug. Internal boll damage increased following initial bifenthrin sprays.
Management strategies for 2025 include scouting, pre-bloom with a sweep net and square retention; and post-bloom with a drop cloth, especially with dirty blooms.
If producers have problem areas, implement ThryvOn at planting or Diamond. Neither is a cure all but have value in plant bug management programs.
Diamond is active on nymphs only and does not control adults. It has good residual activity with six ounces at two weeks and nine ounces at three weeks. Ideally, growers need to apply in front of a hatching plant bug. It is an easy decision if a farmer knows nymphs will establish.
“Diamond is one we have not used a lot in cotton. It’s got a fit in other parts of the country where plant bugs are more common. Our growers are going to have to learn about this and see if it fits their operation,” Roberts said.