Coming soon to a field near you: Binodoxys communis. At least that's the hope of Kelley Tilmon, South Dakota State University soybean research and Extension entomologist. She's part of a group of 14 scientists from five north-central states and the USDA who are overseeing the Binodoxys communis release in South Dakota and the larger region.
The insect is a natural predator of soybean aphid, an Asian insect first discovered in the U.S. in 2000.
“Soybean aphid is seldom a pest in Asia, largely because there is a large suite of natural enemies,” says Tilmon. “When an herbivorous insect gets in accidentally, it usually gets in without the natural enemies that help control it.”
One solution to that control in the U.S. is to try to introduce Binodoxys communis here. And, because it's a soybean aphid specialist, it's not likely to cause problems for other non-pest insects. It also doesn't stray far from the habitat of its host insect, making it unlikely to become a nuisance for humans.
Binodoxys communis, as a part of its reproduction cycle, deposits an egg inside a living aphid. The egg hatches into a larva that feeds inside the aphid. The aphid eventually dies and forms a protective shell around the developing parasitoid pupa. When the adult parasitoid exits, the mummified aphid shell is left behind.
Tilmon does caution that only about half of the parasitoid introduction attempts have resulted in successful establishments, but even if the Binodoxys communis is successful, producers will still need to monitor for aphid and use pesticides for control. They will, however, need to use less pesticide, and the parasitoid control is free.
“For soybean farmers, I think it will be very helpful to have more options to control soybean aphids,” says David Iverson, chairman of the South Dakota Soybean Research & Promotion Council. “Currently, farmers can control aphids with pesticides. To have the aphid population reduced with natural predators would be great for producers and good for the environment.”
Since approval of the release program in 2007, there have been 10 releases of the insect in eastern South Dakota.