Aphids on a soybean leaf.

MN Impact: Discovering Insecticide Resistance in Soybean Aphid

August 9, 2018

Objective

Research will support a more sustainable, diverse and resilient food system (Measure: number of new or improved innovations developed for food enterprises. Measure: number of new diagnostic systems analyzing plant and animal pests and diseases).

Issue

Soybean aphid (Aphis glycines) has been wreaking havoc on Midwest soybeans since it was first discovered in 2000. While careful management practices have helped keep yields up, the possibility of aphids having resistance to insecticides remains a key concern.

What has been done

The first documented cases of soybean aphid insecticide resistance in North America took place in 2015 but the method for determining resistance was time-consuming and costly.

In 2017, Robert Koch and his team developed and validated a more efficient glass-vial diagnostic concentration bioassay for two pyrethroidinsecticides (lambda-cyhalothrinand bifenthrin).

Results

With this new method, a multistate team of researchers quantified the susceptibility of 23 populations of soybean aphid from Minnesota, Iowa, South Dakota, North Dakota and Manitoba. This work has shown that soybean aphid insecticide resistance has persisted over three years and is now widespread.

In response to this new threat to soybean production, a multistate insecticide resistance program for soybean aphid has been established and will assist in developing a regional management plan.