Auburn University entomologists have discovered and identified a wasp that could provide benefits to soybean producers and other farmers.
Though only about the size of a pinhead, the newly detected parasitoid wasp, Ooencyrtus nezarae, can do plenty of damage to the kudzu bug, a quarter-inch-long invasive pest to soybeans and other legume crops in the Southeast.
Researchers in Henry Fadamiro’s, associate dean for research for the College of Agriculture and associate director of the Alabama Agricultural Experiment Station, lab were the first to detect the wasp’s presence in North America.
Fadamiro and his team’s findings were published 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 the
Fadamiro and Rammohan Balusu,
Auburn research entomologist Charles Ray and entomologist at the USDA Smithsonian Institution in Washington, D.C. Jason Mottern are also
The parasitoid wasp is the second plant-killing bug, attacking wasp to be identified in the U.S. The first, Paratelenomus
“It is exciting to know that many natural enemies are in the field helping to keep kudzu bug populations under control,” Ademokoya said. “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 plant-killing bug, also known as the kudzu bug, is native to Asia and was first reported in the U.S. in 2009 in Georgia. Although it feeds on kudzu, an economically important invasive weed native to Asia and familiar to southerners, it also devours soybeans and other legume crops, causing
In 2017, Alabama farmers harvested approximately 345,000 acres of soybeans with a production value of more than $150 million.
The kudzu bug has emerged as the top yield-limiting pest of soybeans, which rank as the second most planted field crop in the United States with an estimated annual market value of approximately $39 billion.
The pest rapidly expanded its numbers across many Southern states including Alabama, South Carolina, North Carolina, Florida, Tennessee, Mississippi, Virginia, Kentucky, Louisiana, Arizona, Maryland
The parasitoid wasp, 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.
Despite the parasitoid wasp’s high parasitism rate of the kudzu bug, it has a short period of activity. Continued research will be necessary to identify tactics for the use of the insect to biologically control the pest on farms, Fadamiro said.
“We need to conduct monitoring to know the distribution of the parasitoid in the United States and to determine its seasonal phenology in the field — when it is not active and when it is most active,” Fadamiro said. “We also are interested in studying the nutritional ecology of this insect and strategies for its conservation in the field. We don’t want to spray toxic chemicals when it is most active.”
Fadamiro said there are numerous ways to use natural enemies in production agriculture including introducing them into areas where they are not already present and preserving them where they are naturally occurring.
He said farmers can plant host flowering plants around a field so the nectar will attract and keep the beneficial insect in an area.
“If we conduct a survey and find the insects are only in central Alabama, then we can capture and relocate them to other areas of the state where the kudzu bug is a threat,” Fadamiro said. “We want to make sure this finding is useful to the farmers who need it most.”
Fadmiro said there’s a risk in assuming the known natural enemies of the kudzu bug will eliminate the threat.
“While the incidence of the kudzu bug has declined in recent years, there could be many factors involved including weather conditions and other natural enemies, so we need to continue this work,” he said.
The research leading to the discovery of the parasitoid was supported by an Agriculture and Food Research Initiative Competitive Grant from the USDA National Institute of Food and Agriculture and by the Alabama Agricultural Experiment Station.