On December 15, 2017, the U.S. Environmental Protection Agency (EPA) announced its release of preliminary ecological and human health risk assessments for three neonicotinoid insecticides: clothianidin, thiamethoxam, and dinotefuran, as well as a preliminary ecological risk assessment for imidacloprid, assessing risks to birds, mammals, non-target insects, and plants. The assessments are available in the dockets linked below:
EPA also released new cotton and citrus benefits assessments for foliar applications of the neonicotinoids as well as its response to public comments on the 2014 Benefits of Neonicotinoid Seed Treatment to Soybean Production. These are available in Docket No. EPA-HQ-OPP-2014-0737.
For all of the dockets listed above, EPA states that it is particularly interested in public comment on the benefits for cotton and citrus, since previous assessments identified potential risks to pollinators. Further, EPA states that “early input from the public will be helpful in developing possible mitigation options that may be needed to address risks to bees. Among the benefits identified, the neonicotinoids were found to be critical for management of Asian citrus psyllid -- which causes citrus greening, a devastating pest for citrus growers, and for control of plant bugs and stink bugs in cotton.” The comment period will begin when the Federal Register notice is published and will be open for 60 days. EPA states that it plans to release the final pollinator risk assessments and proposed interim decisions for these chemicals in mid-2018.
These documents EPA has added to the dockets linked above add to a trove of continued EPA assessments of the neonicotinoid compounds. In January 2016, EPA assessed the risks to pollinators and concluded that the seed treatment uses are generally not of concern, but that there are possible risks of importance in citrus and cotton production. This is why this recent batch of documents, including the benefits assessments of the neonicotinoid products in citrus and cotton production, along with the long-awaited response to comments to EPA’s earlier benefit assessment of the soybean use, has been anticipated for some time. In summary, the benefits assessment for both cotton and citrus indicate significant benefits for these uses. And regarding the earlier benefits assessment of soybeans, EPA now concludes that it underestimated the benefits of the soybean uses generally and in particular has concluded significant benefits in some regions from soybean seed treatments.
With EPA now concluding these uses have significant benefits, there may be some need for risk mitigation of certain use patterns, but generally the estimated benefits will offset and preclude the imposition of more general label restrictions for these crops. For example, the benefits assessment for the citrus uses states flatly that the continued sustainability of the citrus crop requires continued use of the neonicotinoid products (to control the insect that is the vector for citrus greening disease).
Regarding other formulations and risk to organisms other than honeybees, the documents do identify some possible adverse impacts on non-target aquatic insects, birds, and possibly some aquatic invertebrates. These initial findings will likely continue to fuel the debate about the impacts of neonicotinoid use. Registrants will likely submit significant amounts of rebuttal data to further refine these risk estimates and currently do not anticipate significant additional label restrictions as a result, especially since EPA has concluded these products have more significant economic benefits which will be part of any risk-benefit considerations as EPA moves forward.
More information on neonicotinoid issues is available on our blog under key word neonicotinoids.