The brown marmorated stink bug was found in several soybean fields last year in populations large enough to notice after having entered the state a few years ago.
Entomologists with Ohio State University’s College of Food, Agricultural, and Environmental Sciences are developing a new fact sheet to provide soybean growers updated information on the stinky pest that has the potential to become a significant problem for Ohio growers.
Stink bugs, known for their “sweaty feet” smell when squashed or irritated, have now made their way into Ohio soybean fields in numbers not previously experienced in the Buckeye State, according to Ron Hammond, an Ohio State University Extension entomologist. Because the problem has gotten so bad, OSU entomologists are working on a new fact sheet to address growers’ concerns, he said.
A native of eastern Asia, the brown marmorated stink bug was first identified in the U.S. in Allentown, Pa., in 2001. The brown, three-quarter-inch insects are known to feed on a wide range of crops, including apples, peaches, tomatoes and soybeans.
Likewise, Hammond said, sightings of larger-than-usual numbers of green stink bugs have also been reported in Ohio soybean fields, as well as reports of the red-shouldered stink bug, which is a newer pest in Ohio.
“Up until recently, stink bugs weren’t in populations large enough to cause a concern in Ohio,” he said. “But as these bugs begin to increase in numbers across the state, the concern for soybean growers is the potential for yield declines due to the pests, which use their piercing-sucking mouthparts to feed on the plant seeds.
“Since these bugs can cause direct damage to the seed, it doesn’t take a huge number of the pests to cause an economic loss, particularly for food-grade soybeans and soybeans grown for seed.”
Hammond said last year was the first time that Ohio growers reported larger amounts of green stink bugs in their fields. The bugs are typically more prevalent in southern states. But with warmer temperatures in recent winters and summers, more of the bugs have begun traveling north, he said.
“We had reports of fields at economic levels last year in Ohio, which are fairly rare to see in our area,” Hammond said. “And we anticipate that to become more prevalent throughout the state.”
Since many growers were delayed in planting, it may be increasingly important to scout for stink bug populations in fields this year.
“I think what we may have with the timing of this year’s soybean plantings are small beans when stink bugs start moving in,” said Wayne Bailey, a professor at the University of Missouri. “Data shows that at the R6 stage there is no longer an effect on the pods, so it is vital to scout between R1 and R5.”
To scout, growers need to take multiple, 10-sweep samples with a sweep net in multiple locations throughout the field. Then, average the number of stink bugs in the samples.
If growers find themselves with high populations of stink bugs in a field it may be necessary to use an insecticide treatment to control the pests.
“Farmers need to make sure once they realize they have a large population in a field to spray it before the feeding frenzy begins,” Bailey said. “They may want to do that a bit before threshold, which is now an option because of the high commodity prices. The affordability per acre to treat insects and protect the yield is there for this year’s growing season.”