Stink bug that’s new to US munches nuisance kudzu, but also threatens bean crops in South

Kudzu-munching bug also threatens US bean crops

ATLANTA — Researchers recently found an insect in north Georgia that has never before been reported in the Western Hemisphere — and its arrival could be both a blessing and a curse.

Some might celebrate the arrival of the kudzu-munching bug, which could help control the invasive vine that drapes much of the South. However, the bug also feasts on valuable crops like soybeans and other legumes.

As of Nov. 12, the insect was reported in nine north Georgia counties, mostly on homes and other buildings with nearby kudzu patches. Experts aren’t sure yet how fast or wide the bug will spread or how damaging it might be to crops.

“I think in time it’s going to spread significantly,” said Dan Suiter, an associate professor of entomology at the University of Georgia’s Griffin campus. “But only time will tell.”

Suiter and Lisa Ames, director of UGA’s Homeowner Insect and Weed Diagnostics Lab, first received specimens of the bug from pest control companies and county agricultural officials in mid-October. Neither had ever seen it before and both initially misidentified it.

Just before Halloween, Dow AgroScience field researcher Joe Eger visited the UGA campus, and Suiter happened to show him a specimen. That turned out to be a lucky break.

“There are literally five people in the U.S. who could’ve identified this insect,” and Eger was one of them, Suiter said.

An insect enthusiast who has devoted a lot of time to studying stink bug varieties, Eger quickly recognized the bug as a bean plataspid, a native of India and China that is commonly called lablab bug and globular stink bug.

It was not good news.

The brownish bugs have a narrow head and a wide, rounded back end and are a little bigger than the eraser on a pencil, Eger said. They waddle a bit when they walk but fly quickly.

As a variety of stink bug, the insect gives off an odor when threatened that Suiter describes as “a mildly offensive, bitter smell.”

Kudzu was introduced into the U.S. from Asia at the 1876 Philadelphia Centennial Exposition, according to The Nature Conservancy Web site. From the mid-1930s to the mid-1950s, farmers in the South were encouraged to plant it to prevent soil erosion. But in the warm Southern climate, the invasive species quickly got out of control, growing at a rate of up to a foot a day and smothering other plants.

It’s unknown how the bug got here, Suiter said, adding that it could have hitched a ride in someone’s suitcase or on a plant sample brought into the country.

When the new bug was identified, Suiter reached out to see if any kudzu experts knew if the bug had ever been imported from Asia to control the plant. However, he was told it was ruled out because of its taste for soybeans.

The stink bug feeds on the seeds of the beans and other legumes, and also sucks juices from plants. That leaves holes that can cause the plant to wilt or allow bacteria to seep in.

As host plants die off in the cooler fall weather, the bugs are looking for places to spend the winter, settling into attics and cracks in wood siding on houses, Suiter said.

Jim Chase, an entomologist for pest control company Terminix, said customers in several north Georgia counties started calling with complaints about the bugs several weeks ago, but he wasn’t sure how many confirmed cases they’d had. Some of the bugs were discovered by Terminix agents who were called for other problems.

The bug was discovered after most legume crops had been harvested, and it has only been spotted in the northern part of the state so far, while most farms are in the south. After waiting out the winter, the bugs will likely come out again in the spring to lay eggs, Suiter said.

And they can quickly hitch a ride to other parts of the state on cars and clothing.

So far, no sightings of the bug have been reported outside of Georgia, but state and federal officials are closely watching the insects.

The Georgia Department of Agriculture is working with UGA and the U.S. Department of Agriculture to learn more about the bean plataspid and what might be done to control it, Assistant Agriculture Commissioner James Sutton said in an e-mail. Growers should be aware of the new pest and should check their crops carefully, he wrote.

“While the insect is new to the U.S., early indications are that our agronomic practices should be able to control it,” he wrote. “Eradication does not appear to be likely, as the insect appears to be widespread and well-established.”