Over the past year, soybean farmers in South Carolina have been dealing with a new type of pest.
They are called bean plataspids, but are better known as “kudzu bugs.” They resemble boxy brown ladybugs and are a Chinese insect that is not native to America, but believed to have first arrived in the Southeast in 2009 aboard a flight in Atlanta.
Since they have no natural predators in the area and cycle through several generations each season, they quickly spread across the region. Agriculture officials suspect the insects are now in all 46 South Carolina counties.
Entomologists aren’t certain how best to deal with the new pest, which emits a foul odor when threatened. They recommend that farmers use organophosphate and pyrethroid insecticides, but otherwise are struggling to stop the plataspid’s rapid spread across Georgia and the Carolinas.
“This insect can cause anywhere from zero percent losses in soybeans… up to about fifty percent,” said Jeremy Greene, an entomology professor and specialist at Clemson Extension Services’ Edisto Research and Education Center in Blackville, “Fifty percent is a lot.”
The plataspid attaches its mouthparts to legume (bean) stalks and then sucks out the plant’s nutrients. It’s known as the “kudzu bug” because of its affinity for kudzu– another exotic invasive species from Asia that has overrun the South. Researchers at the University of Georgia found the insect reduced kudzu growth by a third.
But that means homeowners who live near kudzu plots should watch out, says South Carolina Forestry Commission entomologist Laurie Reid. “You’re not just going to find one of these randomly on your house. You’re going to get tons of them.” She said she noticed over 100 in the yard of her house in Columbia.
The plataspids like to seek shelter over the winter, which means they will try to get indoors. Reid warns homeowners not to squish the bugs (which will release their foul odor), but to instead vacuum the insects up and empty the bag outside.
However, she cautions against using pesticides in a personal yard, since it will likely kill native, harmless insects as well.
Researchers at Clemson and elsewhere are trying to figure out how to check the plataspid’s population growth. One idea is to import a parasitic wasp that is also native to China and feeds exclusively on the kudzu bugs. However, Greene said experts are studying to make sure the wasps don’t have other, unintended effects on the local flora and fauna.
“We haven’t had a lot of time to come up with an answer,” he said, “That’s the thing that I would stress, that folks just be patient with the Extension Service and universities that are researching this problem.”
Reid says the plataspids are likely here to stay, much like the ladybug– a fellow invasive insect that is now recognized and accepted by South Carolinians.