Roundup Shown to Kill Bees— But Not How You Might Expect

April 20, 2021 | Roundup products manufactured by Bayer-Monsanto kill exposed bumblebees at high rates, according to a study published in the Journal of Applied Ecology, which points to undisclosed inert ingredients (those that typically make up a majority of the product formulation) as the primary culprit. Roundup products have become synonymous with their main active ingredient glyphosate, but Bayer- Monsanto has been quietly reformulating its flagship product with different herbicides in a likely rebranding attempt, as glyphosate cancer lawsuits drag down the company. The study reveals that these new Roundup products present the same hazards to pollinators as glyphosate-based formulations, raising important questions about the pesticide regulatory process. The “no glyphosate” formulation of Roundup being sold in the UK and European Union is different than “no glyphosate” formulations being sold in the U.S. In the U.S., Bayer- Monsanto is selling a product line called Roundup® for Lawns which contains four different main active ingredients: dicamba, MCPA, quinclorac, and sulfenzatrone. The UK/EU version of the product appears to only contain acetic acid (vinegar), a least-toxic substance that presents moderate hazards to pollinators from exposure. However, the results raise the likelihood that it is primarily the so-called “inert” materials not disclosed on the Roundup label that are harming pollinators. [Straw, Edward Roundup causes high levels of mortality following contact exposure in bumble bees. Journal of Applied Ecology. 58:1167– 1176, 2021.]