The soybean industry, worth $27 billion last year, is exploring ways to combat aphids. Aphids can destroy up to 40% of a farmer's crop.

Using Binodoxys communis against soybean aphids: Researchers look for mummies, the darker brown objects on the soybean leaf shown above, to gage the effectiveness of the beneficial insect in controlling soybean aphids. The light green spots on the soybean leaf are soybean aphids.Courtesy David Hansen, Minnesota Agricultural Experiment Station

With insecticide costing $10 to $15 per acre, it can add $8,000 or more to his costs. But the difference between spraying and not spraying can be 10 bushels or more per acre at harvest, said Iverson, president of the South Dakota Soybean Research and Promotion Council.

Biological warfare against soybean aphids

Another possibility researchers are looking at is Binodoxys communis, a tiny, parasitic insect that inserts an egg into the aphid. The egg hatches into a larva that kills the aphid, feeds on it and emerges as an adult from what becomes a mummified aphid shell.

Minnesota winters may be too cold

Initial counts of Binodoxys communis that survived through the winter were low. Plan B is to look at a couple other species of parasitoid wasps.

Learn more

• Biological control research against aphids at the University of Minnesota
• Four page PDF of FAQ about using beneficial insects to control soybean aphids
• Scientists hope tiny insect can help save soybeans, USA Today.