Mid-South soybean producers are encouraged to continue scouting their fields closely for redbanded stink bugs, a pest that can do more severe damage and do it longer into the season than other stink bug species.
The warning came from entomologists in Mississippi, Louisiana and Arkansas during a recent redbanded stink bug emergency forum that was also streamed live and recorded for later viewing. You can view a PowerPoint presentation that highlights key points made during the forum by clicking here.
“Our threshold that triggers pesticide treatments is four redbanded stinkbugs per 25 sweeps instead of nine per 25 sweeps, which is our threshold for native stinkbugs,” said Mississippi State University Extension entomologist Angus Catchot. “We manage redbanded stinkbugs at that same threshold through the R7, or beginning maturity, growth stage. This is a big difference from what we have been used to doing in the past.”
Only three classes of chemicals effectively control redbanded stink bugs: neonicotinoids, pyrethroids and organophosphates, said Jeff Davis, a Louisiana State University AgCenter entomologist. But they need to be rotated to manage for resistance. Growers who want to tankmix an insecticide with their desiccant/harvest aid also need to keep in mind the insecticide’s pre-harvest interval, he said.
The biggest threat from the redbanded stinkbug comes from its ability to damage soybean plants much later in the reproductive stages than producers are used to seeing with traditional stinkbug species. It also inserts its stylet, or feeding tube, deeper into the pod, causing more damage to beans than some other stink bug species.
Don Cook, Mississippi Agricultural and Forestry Experiment Station research entomologist, said redbanded stinkbugs are invasive, non-native pests first seen in the state in 2009. Louisiana producers have been dealing with this invasive pest since 2000.
“They don’t handle cold weather very well, and the winter of 2009 was cold and killed them off,” said Cook, who operates from the Delta Research and Extension Center in Stoneville. “We didn’t really see them in the state again until 2016, when central Mississippi had pretty high numbers of this pest.”
Last winter was mild, giving the pests an opportunity to overwinter in the state.
“They got on weeds in April, and, once they had a foothold, they just moved on up the state,” Cook said. “If we have a cold winter, we may not see this pest again in 2018.”
Catchot said redbanded stinkbugs are most dangerous to soybeans, but, on occasion, they get into cotton and must be treated. This year, they are being found in high numbers in peanuts in south Mississippi.
“Peanuts are likely not affected by them, but they serve as a source to grow the population that may later move into soybeans,” Catchot said.
August’s wet weather has contributed to the problem with this pest.
“Due to the recent heavy rains, many producers have been unable to effectively treat soybean fields for redbanded stinkbugs, allowing their numbers to increase,” Catchot said. “Stinkbugs feed on water-soaked pods, which opens avenues for disease entry. That may further affect the quality of the soybean crop.”
Although it is a devastating pest, good scouting and timely applications of pesticides can control it.