Wasps used to fight soybean aphids

University of Minnesota researchers, in an effort to control the damaging crop pest, are field testing a sting-less wasp (Binodoxys communis) imported from China that kills soybean aphids.

The soybean aphid first appeared in Minnesota fields in 2000 and costs soybean growers an estimated $200 million annually in lost crop yields and spraying costs in Minnesota.

"The soybean aphid was imported without any of its natural enemies -- the organisms that keeps aphids in check in China," said University of Minnesota entomologist Dave Ragsdale. "Our researchers and Extension experts are working to provide that check and balance system."

Binodoxys communis was approved for release based upon four years of laboratory safety testing, Ragsdale said. However, researchers said 11 other species and strains of sting-less wasps are also being evaluated and some that have shown promise from both safety and efficacy standpoints might be field tested next year.

The origin of the Asian aphid's entry into the United States remains undetermined, but it's believed Chicago was at the epicenter of the initial distribution in the mid 1990s.

Copyright 2007 by United Press International