Research HighlightsMonitoring and Managing Stink Bugs in Texas
By Laura Temple
Stink bugs cause significant damage as a major soybean pest in the mid-Gulf Coast region of Texas, one of the state’s primary soybean-production areas. The pests also attack cotton, grain sorghum and corn, but soybeans filling pods actually will draw stink bugs out of cotton fields, according to Stephen Biles, an integrated pest management (IPM) Extension agent for Calhoun, Victoria and Refugio Counties in Texas.
“Soybeans attract stink bugs, but I would rather eat soybeans, than cotton, too.” Biles explains, “Soybean acres in this region have been reduced in part because of stink bugs. They are difficult to control, and they can cause 30 to 40 percent damage, which can cost up to $2 per bushel in quality dockages when selling them.”
To help soybean farmers fight this pest, the Texas Soybean Board supports Biles as he monitors soybean fields for stink bugs and shares pest pressure information. The species complex in the region includes green, southern green, brown and red-banded stink bugs.
“Options for stink bug control are limited to pyrethroids and acephate,” he says. “Red-banded stink bugs have developed resistance to pyrethroids, and acephate doesn’t always work well, either, creating even bigger challenges.”
When opportunities arise to work with a grower to conduct an insecticide field trial to compare efficacy of stink bug control, Biles takes advantage of them. However, because most farmers are very proactive with stink bug control, it isn’t possible for him to do a trial each year. In 2020, he focused on surveying fields, scouting with sweep nets and informing farmers when populations reached economic threshold levels.
“The base economic threshold for stink bugs in soybeans is 36 stink bugs per 100 sweeps,” he explains. “However, the economic thresholds for stink bugs vary by the predominant species being found. For red-banded stink bugs, the economic threshold is just 12 per 100 sweeps.”
Effective insect control is key to reducing damage and managing profitability in Texas soybeans. Regular updates on the current stink bug complex, insect life stage and population density during the season help regional soybean farmers make sound treatment decisions.
“For example, I anticipated heavy stink bug pressure in 2020 because of a mild winter, but populations ended up being relatively low,” Biles says. “So many factors impact insect populations that it is hard to predict pressure. A few really dry days or really wet days at key points in insect life cycle can significantly impact population density. That’s why we monitor fields every season.”
In addition to stink bugs, Biles scouts soybean fields for caterpillar pests, but they are typically not an issue in Mid-Coast Texas soybeans.
“The Texas Soybean Board’s purpose is to use checkoff funds for production research to improve the soybean industry in Texas,” says Texas Soybean Board Chairman Daniel Berglund, a farmer from Wharton, Texas. “Our research efforts are focused on improving soybean production yields and quality.”
To find research related to this Research Highlight, please visit the National Soybean Checkoff Research Database.