Auburn University finds second kudzu bug natural enemy

kudzu bugs
The kudzu bug has emerged as the top yield-limiting pest of soybeans — photo courtesy Auburn University

Auburn University entomologists have discovered a tiny wasp that could provide a huge benefit to soybean producers in Alabama and other Southern states plagued by the kudzu bug.

Though only about the size of a pinhead, the newly detected parasitoid wasp, Ooencyrtus nezarae, can do plenty of damage to the kudzu bug, according to a university news release. Researchers in the lab of entomologist Henry Fadamiro, associate dean for research for the College of Agriculture and associate director of the Alabama Agricultural Experiment Station, were the first to detect the wasp’s presence in North America.

The team published its findings in a recent article in the Journal of Insect Science. Blessing Ademokoya, an Auburn graduate researcher at the time of the study and now a doctoral student at the University of Nebraska–Lincoln, is lead author of the article. Fadamiro and Rammohan Balusu, research fellow in the Department of Entomology and Plant Pathology, are co-authors, as are Auburn research entomologist Charles Ray and Jason Mottern, entomologist at the USDA Smithsonian Institution in Washington, D.C. Ray and Mottern assisted in final identification of the wasp.

Ooencyrtus nezarae is the second kudzu bug–attacking wasp to be identified in the United States The first, Paratelenomus saccharalis, was discovered in Georgia in 2013.

“It is exciting to know that many natural enemies are in the field helping to keep kudzu bug populations under control,” Ademokoya said in the release. “And, with this latest addition, we have a potential explanation for the decline observed in kudzu bug densities across several locations in the southeastern U.S.”

The kudzu bug, native to Asia, was first reported in the United States in 2009 in Georgia and has since spread throughout most of the South and Mid-South. Although it feeds on kudzu, it also devours soybeans and other legume crops, causing significant yield loss in highly infested fields.

Ooencyrtus nezarae, which was found during field surveys in Alabama, is reported to parasitize eggs from a variety of plant bug families in China.

“Until now, the distribution of O. nezarae has been limited to China, Japan, Thailand, South Korea and Brazil,” Fadamiro said. “This is the first report of the parasitoid in North America. The high rate of parasitism—82.8 to 100 percent—recorded in our study indicates that the parasitoid may serve as a potential long-term solution for managing kudzu bug.”

Despite O. nezarae’s high parasitism rate of kudzu bug, it has a short period of activity, and Fadamiro said continued research will be needed to identify tactics for using the insect as biological control.

Populations of kudzu bug peaked in 2013. Why that occurred remains unknown, but it could involve many factors, including weather and other natural enemies.

 

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