Farmers in the Southeast U.S. might have a new solution to the soybean-damaging kudzu bug. Graduate research assistant Julian Golec under the direction of Alabama Agricultural Experiment Station Scientist Xing Ping Hu discovered natural enemies to the pest that might bring farmers relief.
Kudzu bug is widespread in Asia and can be found in Georgia, North Carolina, South Carolina, Virginia, Alabama, Tennessee and Florida. The pest uses piercing and sucking to reach phloem in soybeans, which results in nutrient and moisture loss, opening the plant up to pathogens. Georgia has recorded up to 47% yield loss from the kudzu bug. The pest overwinters near kudzu plants or soybean fields in residue, according to North Carolina State University Extension.
Farmers might have some relief from the pest if native insects are allowed to survive and attack. Golec discovered an indigenous tachinid fly can use adult kudzu bugs as repositories for eggs. He found fly larvae in 10% of kudzu he dissected. The native fly species is widely spread throughout North America.
Kudzu bugs are highly adaptable, which makes them challenging to overcome. A single bug can fly 30 miles, and females can mate and store eggs until weather favors release, even when no males are present. “The discoveries of the parasitic fly and parasitic eggs wasp as natural enemies of kudzu bugs could be game-changers in reducing the invasive insects’ future populations,” Hu says.
At Clemson University, Graduate Research Assistant Francesca Stubbins made the newest discovery of another natural enemy to kudzu bugs, nematodes. While dissecting the pest Stubbins found Mermithidae nematodes in the abdomens of female kudzu bugs and later in male and nymphs. The nematodes enter kudzu as immature nematodes and develop inside the pest and emerge into the soil to become adults. When they lay eggs it starts the process over again.
Ten pesticides are currently labeled for kudzu bug control in the U.S., according to Alabama Agricultural Experiment Station. Some are concerned about the impact pesticides could have on the native fly and egg wasp. Hu and Golec are being joined by Xiangli Dong of Qingdoa Agricultural University in China’s Shandong Province to study the effect of pesticide applications on natural enemies.
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