NAICC: Insect Challenges on the Horizon

The perfect storm could be brewing for a soybean insect crisis to occur within a year or two.

You may have heard about the close call that Lorsban (chlorpyrifos) could have lost its label, including on soybeans. Chlorpyrifos is one of only a few insecticides that will control spider mites in soybeans. The fact that the active ingredient has been widely used for more than 50 years without significant problems is a testament to the pesticide’s utility and safety.

Currently, the synthetic pyrethroid class of insecticides is under review by EPA. For more than 40 years, synthetic pyrethroids have been a reliable and safe class of agricultural insecticides. The discovery of this class of insecticides, which are based on a natural compound produced by chrysanthemums, was a breakthrough because of its low mammalian toxicity. The lack of environmental or safety issues shows how successful synthetic pyrethroids have been.

This past summer, a newer active ingredient, sulfoxaflor (Transform), lost its soybean label due to concerns about possible effects on pollinator insects, though the insecticide targets only piercing and sucking insects once it dries on foliage. One concern about pollinators and insecticides involves application during flowering when honey bees and other pollinators are present. Soybeans, especially the non-determinate varieties in northern climates, are somewhat unique because flowering occurs during a long period of time. If applications were to be restricted to crop stages other than flowering, we would lose the ability to control mid- and late season pests such as soybean aphids and two-spotted spider mites.

We are at risk of losing some of our most promising insecticides–the neonics–because of trace amounts of the pesticide from seed treatments. In this form, the insecticide can be harmful to honey bees.

WHAT’S AT RISK

When we lose the label for a pesticide active ingredient, we also lose a powerful tool for resistance management. Insect populations have been well-known to develop resistance to insecticides when the same active ingredient is used repeatedly on a crop. Using tank mixtures or rotating modes of action discourages the development of insecticide resistance. We need many different modes of action in our toolbox for each crop.

The vast majority of negative effects on pollinators are not due to an insecticide’s inherent toxicity, but they’re rather due to an application method, timing or formulation of the pesticide. As a society, we must realize that it will occasionally be necessary to apply insecticide to plants during flowering. If we make the right choices, we can produce food and fiber and minimize any negative effects on beneficial insects.

Farmers and agronomists need to be actively engaged on issues of pesticide labeling. When it comes to the emotional topic of honey bees, it seems that EPA will receive a plethora of comments against the use of all insecticides. Thankfully, the EPA genuinely welcomes real-world comments from agronomists and farmers that support specific needs.

AN EASY STEP TO MAKE A DIFFERENCE

It is incredibly easy to provide comments to EPA about proposed label changes for a pesticide. Go to www.Regulations.gov, and use the search box to type in the active ingredient of concern. Then, a list of dockets will appear. If comments are currently being accepted on a docket, you can click on a link and easily provide your comments.

Finally, we also need to educate ourselves about ways to reduce the risk of pesticide applications for pollinator insects. A lot of great information is available. Crop protection companies have responded with informative websites such as beecare.bayer.com and honeybeehealthcoalition.org.