Curbing pesticide threats to bees

Berry Brosi, a bee biologist, is an assistant professor of environmental studies at Emory University.

Bee populations are declining and several culprits contribute: parasites and diseases, pesticides, lack of flowering plants to feed on and management practices. Scientists, conservationists, government agencies and beekeepers are working hard to figure out ways to reduce these challenging problems.

One concrete action we can take is to reduce exposure to pesticides that can harm bees and other pollinators. Recently, Emory University announced that it will take an important step toward protecting bees by banning a class of pesticides known as “neonicotinoids.”

Though relatively new on the market, neonicotinoids are the most-used class of insecticides on earth. For example, one chemical in this class, Clothianidin, is used in the production of the vast majority of corn grown in the United States. Neonicotinoids are also commonly found in many household garden chemical products and greenhouse-grown ornamental plants that are pre-treated prior to sale in nurseries. Some nurseries in the U.S. are refusing to sell plants pre-treated with neonicotinoids, but most nurseries have not followed suit.

Scientific evidence has been mounting from a range of studies that neonicotinoids are particularly damaging to bees. Neonicotinoids not only kill bees, they can also affect them in other ways. Even at low concentrations, sometimes measured in a few parts per billion, neonicotinoids can impair bee immune systems, learning, foraging, and navigation.

Bees provide us with one of every three bites of food that we eat via pollination of food crops. Crops that are dependent on bee pollination represent many of the most nutritious and vitamin-rich fruits, vegetables, nuts and seeds in our diet. Bees also contribute to our economy in unexpected ways, like the pollination of cotton. Pollinators also play a critical role in natural ecosystems by pollinating wild plants.

Research journals recently synthesized studies on neonicotinoids. This review clearly shows that these chemicals are accumulating in water and soil and that their use can have negative impacts on species beyond pollinators, including birds. The EPA is now conducting a full review of the safety of neonicotinoids but results are not expected until 2018.

Emory thinks that is too long for bees to wait. I am proud to work at an institution that’s taken a concrete step toward improving pollinator health.