As the growing season progresses, stinkbugs continue to increase their impact on soybeans. Syngenta is reporting increasing populations of stinkbugs into the Midwest.

The company is encouraging growers to remain diligent in their scouting efforts. While this pest has typically been an economic problem for Southern U.S. soybean growers, populations are now appearing in fields farther into the Midwest, threatening yields more widely than ever before.

Stinkbugs are sucking pests, so their damage may not be as outwardly apparent as defoliating insects. They pierce soybean pods, then feed on plant fluids, causing shriveled, damaged seeds and flattened pods. The reduced quality and yield loss can be economically detrimental to a grower’s crop.

There are several types of stinkbugs that growers should look for when scouting. The most common are the green stinkbug, the brown stinkbug, the red-shouldered stinkbug, the red-banded stinkbug and the brown marmorated stinkbug.

In the Southeast this year, growers were initially seeing brown stinkbugs, but green stinkbug populations have made a strong appearance later in the season.

“Early-maturing soybeans served as a trap crop for stinkbugs,” said Ron Smith, Extension entomologist at Auburn University. “Populations reached economic thresholds, and early-podding soybeans had to be sprayed. As the season winds down, stinkbugs will be concentrating in soybeans as other crops dry down.”

Scouting for stinkbugs in soybean fields should begin as soon as plants start putting on pods. Since stinkbugs have two to three generations per season, there is plenty of time for them to do damage, so scouting throughout the entire season – up until pods reach maturity – is vital.

“This year, stinkbug populations have continued to build as soybeans reach R5 and R6,” said Gus Lorenz, Extension entomologist at the University of Arkansas.

Growers should focus their scouting efforts on fields as they reach those growth stages and only spray when populations reach economic thresholds in order to get the most yield benefit from their input.

Stinkbugs are also making their way farther into the Midwest than in previous years. Brent Rains, entomologist and field consultant for Crop IMS, said this year has had the highest number of stinkbugs he’s ever seen in southern Illinois.

“I used a sweep net in the soybean canopy, and I could not believe the number,” Rains said. “I was getting three to four times our economic threshold for stinkbugs, and the plants weren’t even at full flower yet.”

Growers are being encouraged to contact their agricultural retailer or university Extension Service to determine the recommended economic threshold for their area. Frequent, visual scouting can help growers identify the pest problem in their fields, then sampling several different sites within a field with drop cloths or sweep nets can indicate population levels.

“Since this pest is spreading into regions where it hasn’t previously been a problem, growers may need to scout more actively than before,” said Brent Lackey, insecticide product lead at Syngenta. “They should have a management plan in mind so that if pest populations reach threshold levels, they can promptly apply an insecticide like Endigo ZC before the stinkbugs cause reduced quality and rob them of yield.”

More information about Endigo ZC and more tips for scouting are at the Syngenta Tools to Grow More Soybeans resource page link.