Researchers Discover the Brown Marmorated Stink Bug's Winter Hideout

While inspecting for BMSB in the woods, researchers observed tree characteristics such as moisture level, type, size, and surface permeability. Source: D. Lee, USDA Agricultural Research Service

Researchers believe they have identified where brown marmorated stink bug (BMSB) gathers in natural landscapes during winter, and their findings could help farmers manage this invasive insect.

Doo-Hyung Lee, a postdoctoral research associate with USDA’s Agricultural Research Service, wants to understand precisely what the risks are to growers from BMSB overwintering in natural landscapes. Lee works with a team of scientists led by Tracy Leskey at the Appalachian Fruit Research Station in West Virginia.

“We know BMSB aggregate inside human-made structures in very high numbers,” Lee explains. “However, in the natural landscape, BMSB are spread out. They can be anywhere. They can remain unchecked by any management strategies, spreading randomly and building their population.”

If researchers could better understand stink bug behavior in the natural landscape, Lee reasoned, they would be able to develop a defense strategy for growers whose farms are located near woodlands. He and his colleagues ventured out into the woods to gather this information first-hand.

Treasure hunting

Lee began his search on a chilly, overcast, winter afternoon in a desolate Maryland forest. “I felt as though I was hunting for treasure with no map,” he recalls. He and his team randomly mapped out plots of Maryland and West Virginia forest, then explored these areas for BMSB hideouts. After searching among dead trees, both standing and fallen, as well as in leaf litter on the ground, they found 26 aggregations of BMSB, a 3 percent find rate.

Using what they had learned, the researchers developed a more specific profile of BMSB’s preferred winter setting: large, dry, dead standing trees, more than 60 cm in circumference, particularly oak and locust, with porous dead tissue and peeling bark that gives BMSB a place into which to crawl. Lee and his team then returned to the woods, targeting only trees that matched their profile. This time, they found BMSB in 33 percent of trees, a finding that seems to confirm a BMSB preference for this winter refuge.

From forest to farm

BMSB poses a huge risk to agriculture, Lee says, because 11 percent of trees in the natural landscape have the potential to harbor BMSB. Therefore, improving our ability to track BMSB movement from woodlands into agricultural areas is critical.

A treadmill for stink bugs: As the insect flies in circles, the top of this device spins, measuring distance and speed. This baseline information is paired with study of BMSB flight in natural settings. Source: D. Lee, USDA Agricultural Research Service

As Lee tracks the brown marmorated stink bug, he is deploying several high-tech tools, including a flight mill that measures the distance and speed a stink bug is able to fly. He hopes to publish detailed information about the insect’s flight capacity within the next year. For now, he cites Asian studies suggesting that BMSB is able to fly long distances and find new cultivated crops readily.

Lee is also pioneering use of harmonic radar to track stink bugs by mounting a tiny antenna to the back of the 17-mm-long insect. This device will relay signals to researchers wearing equipment that can reliably detect tagged bugs up to 50 meters away.

Humankind’s best friend soon will join the defense against its new pest, Lee predicts. Dogs trained to detect the scent of BMSB will make it easier to monitor and manage BMSB in agricultural areas.

Outbreak pest

BMSB is characterized in Asian studies as an outbreak pest, which means that the insect might go undetected for months or years before suddenly bursting on the scene in an agricultural area and causing much devastation. Now that we better understand the sites that provide winter refuge for BMSB, Lee believes, we will be better prepared to prevent future invasions of nearby farms.

Assisting Lee in his research were John Cullum, Sean Wiles, Starker Wright, Torri Hancock, Brent Short, and Cameron Scorza. The research is part of a broader Coordinated Agricultural Project entitled “Biology, Ecology and Management of the Brown Marmorated Stink Bug in Specialty Crops” that has been funded through the USDA-NIFA Specialty Crop Research Initiative.

“People are interested in our project because we are asking very basic questions about the biology of the insect that scientists have not looked at yet,” Lee said. “They are curious because our findings characterize the overwintering behavior of BMSB in the natural landscape. People are very excited.”

These words, while attempting scientific understatement, show the exhilaration of the entomologist who just found the keys to the BMSB hideout in the forest.