EPA Finalizes Biological Evaluations Assessing Potential Effects of Three Neonicotinoid Pesticides on Endangered Species

EPA has released its final biological evaluations (BEs) for clothianidin, imidacloprid, and thiamethoxam, part of a group of insecticides known as neonicotinoids, and its responses to comments received on the draft BEs. These neonicotinoids are used on a variety of crops, turf, and ornamentals, and for other residential and commercial indoor and outdoor uses.

In these BEs, EPA evaluated clothianidin, imidacloprid, and thiamethoxam to determine whether they may affect one or more federally listed endangered or threatened (listed) species or their designated critical habitats. These evaluations, which encompass all registered uses and approved product labels for pesticide products containing these chemicals, are part of EPA’s efforts to meet its obligations under the Endangered Species Act (ESA). This work furthers the goals outlined in EPA’s April 2022 ESA Workplan to provide practical protections from pesticides for listed species.

The BEs evaluate the effects of clothianidin, imidacloprid, and thiamethoxam on over 1,700 listed species and over 800 designated critical habitats in the United States, determining that:

  • Clothianidin:
    • Will have no effect on 14 percent of species and 17 percent of critical habitats;
    • May affect but is not likely to adversely affect 19 percent of species and 27 percent of critical habitats; and
    • Is likely to adversely affect 67 percent of species and 56 percent of critical habitats.
  • Imidacloprid:
    • Will have no effect on 11 percent of species and 10 percent of critical habitats;
    • May affect but is not likely to adversely affect 9 percent of species and 7 percent of critical habitats; and
    • Is likely to adversely affect 79 percent of species and 83 percent of critical habitats.
  • Thiamethoxam:
    • Will have no effect on 12 percent of species and 11 percent of critical habitats;
    • May affect but is not likely to adversely affect 11 percent of species and 7 percent of critical habitats; and
    • Is likely to adversely affect 77 percent of species and 81 percent of critical habitats.

The “likely to adversely affect” (LAA) determination means that EPA reasonably expects that at least one individual animal or plant, among a variety of listed species, may be exposed to the pesticide at a sufficient level to have an adverse effect. The likely “take,” which includes unintentional harm or death, of even one individual of a species, is enough to trigger an LAA determination. This is the case even if a species is almost recovered to a point where it may no longer need to be listed. As a result, there are often a high number of LAA determinations in a BE. An LAA determination, however, does not necessarily mean that a pesticide is putting a species in jeopardy.

Because of these findings, EPA has initiated formal consultation with the U.S. Fish and Wildlife Service and the National Marine Fisheries Service (the Services). EPA will be working with the Services throughout the consultation process to clarify how the effects determinations included in the final BEs and comments received on the draft BEs can best inform the Services’ biological opinions (BiOps). EPA’s support is intended to make consultation more efficient and allow the Services to focus their resources on developing additional mitigations to protect species that are the most vulnerable to potential exposures.

During consultation, the Services will develop BiOps, which will include their official determinations of whether a pesticide is likely to jeopardize each relevant listed species or adversely modify its critical habitat, and include any additional mitigation measures the Services develop in coordination with EPA and stakeholders. EPA will then implement any necessary mitigation measures to protect listed species, in collaboration with pesticide registrants.

These final BEs follow the draft BEs for clothianidin, imidacloprid, and thiamethoxam, which EPA released for public comment in August 2021. The draft BEs were developed after the release of EPA’s proposed interim decisions (PIDs) for the neonicotinoid pesticides in January 2020. The PIDs are part of EPA’s registration review process for pesticides, required under the Federal Insecticide, Fungicide, and Rodenticide Act, to identify risks from pesticides and actions that can mitigate risks. In the PIDs, EPA proposed a suite of mitigation measures including annual application rate reductions, application timing restrictions, and measures to reduce spray drift. The Agency anticipates releasing amended PIDs in 2023, which will include updates to some of the previously proposed mitigations, and early mitigation measures to reduce neonicotinoid exposures for listed species. Mitigation measures will be finalized in the interim decisions, which EPA expects to release in 2024. EPA and the Services will consider these final mitigations during consultation.

Read the final BEs for clothianidinimidacloprid, and thiamethoxam.

To learn more about these BEs, see the Frequently Asked Questions.