Like all companies that produce seed for crops that require insect pollination, Monsanto is concerned about honey bee health. Both our vegetable-seed business and our alfalfa-seed business rely on healthy pollinators to be productive. With respect to the question about possible impacts of Roundup herbicide on honey bees, there is sufficient information to conclude that Roundup herbicide and its active ingredient, glyphosate, do not cause adverse effects in honey bees.
In addition to toxicity testing conducted in support of regulatory submissions to the Environmental Protection Agency that demonstrated glyphosate is practically nontoxic to honey bees through both oral and contact exposure, a 2014 publication by Thompson et al. found no adverse effects on adult bees or their young when they were fed environmentally realistic concentrations of glyphosate.
In Thompson et al., the authors describe a method for determining hive level glyphosate exposures to bees and used those exposure data to select doses for a follow-up brood study. (For honey bee colonies, the brood is the immature larval bees raised by the adults.) In phase one, bees from four colonies were allowed to feed on glyphosate-treated purple tansy for seven days. Glyphosate levels were measured in nectar and pollen collected by the bees, as well as in the hive. These concentrations were then used in phase two to assess toxicity to the brood by feeding hives glyphosate in a sucrose solution over seven days. Thompson et al. considered survival of eggs, young larvae and old larvae, as well as pupae weight. No adverse effects on adult bees or bee-brood development were observed in any of the glyphosate‐treated colonies.
Honey bees face many challenges, and solving them will require addressing many possible causes. Recently, a group of interested parties representing bee keepers, honey producers, academics, agricultural companies and government agencies formed the Honey Bee Health Coalition to identify ways to improve honey bee health. The group is working on four areas: forage and nutrition, hive management, crop pest management and outreach. Please visit the link to learn more about the coalition and the solutions it’s pursuing.