Soybean producers in southeast Missouri likely will face a new threat to yields during the 2010 growing season — the red-banded stink bug.

Kelly Tindall, an entomologist at the University of Missouri Delta Research Center, recently found the insects in three Dunklin County soybean fields.

“I doubt they’re doing anything to the late-planted beans that are still in the ground,” Tindall said. Her concern is next year’s crop.

Mississippi has seen red-banded stink bugs jump to 25 percent of the stink bug population since 2008. In Louisiana, the red-banded variety is about 70 percent of the population after five years.

“That’s how quickly they become the dominant pest,” Tindall said.

In her sweeps of the affected fields, the red-banded stink bug accounted for 5.4 percent of the stink bugs recovered. Tindall sampled 14 fields in Dunklin and Pemiscot counties in mid-October.

The red-banded stink bug can be confused with the red-shouldered stink bug because of their similar markings and size. “The key characteristic of the red-banded stink bug is when you flip it over, there will be a spine at the third pair of legs that points up to the head,” Tindall said.

Like all stink bugs, they have sucking mouthparts that allow them to penetrate the pods and remove the contents of developing seed.

Research in Louisiana showed that red-banded stink bugs caged on soybean pods for 72 hours damaged up to 41 percent of the seeds and reduced seed weight by about a third, Tindall said.

“Another troubling thing about this stink bug is that they are harder to kill with insecticides than brown stink bugs,” she said.

In a comparison of treated and untreated plots, red-banded stink bugs reduced yields by 43 percent on untreated plots. “An equally significant part of this study was that the treated plots were treated four times,” Tindall said.

Will the red-banded stink bug survive the Missouri winter? Tindall said that researchers are just beginning to look at the temperature break point. “We know that if they take hold, they go full force.”

Tindall will be discussing red-banded stink bugs during winter crop meetings.