Honey bees and other pollinators are as much a part of agriculture as cattle and corn. We hear a lot about protecting pollinators, as we should, since losses of honey bees since 2006 have been at unacceptable and unsustainable levels. When it comes to protecting pollinators from pesticides there are a few key risks that need to be managed. While this article deals with protecting pollinators from pesticides, I’ll note that pesticides are not the sole cause of pollinator losses and may not be the primary cause of those losses. However, pesticides are under our direct control and we can take steps to minimize their effects on pollinators.
Avoid Contaminating Plants in Bloom
Many insecticide labels prohibit spraying areas in which pollinators are actively foraging. This is subtle language as it does not say do not spray blooming plants. There are times when plants may be in bloom and pollinators are not actively foraging, say for example on cool mornings when the temperature is below 50°F or late in evening when the sun is beginning to go down. It also does not say blooming crops, as pollinators do care if it is a flower on a weed or crop plant. Spraying weeds in flower can be just as hazardous to pollinators are spraying crops in bloom (Figure 1).
Avoid Pesticide Drift onto Colonies
Where we have had direct evidence of pesticide kills of honey bee colonies, pesticide drift over the colonies is frequently the case. To avoid pesticide drift onto honey bee colonies, the first step is to know where the colonies are around fields that will be treated. Get to know your local beekeepers and where they keep their colonies. Work with them to select locations for colonies where they will be set back from areas that will be treated. Having a vegetation buffer strip of trees will help to prevent drift onto the colonies. Don’t spray when the conditions favor drift, especially in the direction of colonies.
Avoid Contaminating Water Sources for Pollinators
Pollinators collect more than just nectar and honey (Figure 2). If you have ever had a teaspoon of honey, you will know that the next thing you need is a drink of water. It is the same with honey bees. Beekeepers will often put out watering stations for honey bees, and just like the colonies themselves, we need to avoid pesticide drift over these areas that would result in contamination. It is best to locate these watering stations is protected areas just like with the colonies.
Managing pesticides to avoid impacting pollinators is required to stay consistent with pesticide labeling.
Ric Bessin, Extension Entomologist