U.S. EPA proposes early mitigation to help protect endangered species from methomyl

In line with the Agency’s commitment to improve outcomes for all federally threatened and endangered (listed) species, the U.S. Environmental Protection Agency (EPA) is proposing revisions to the 2020 Proposed Interim Decision (PID) for methomyl, a type of insecticide. The revised methomyl PID is a pilot case for identifying and proposing early mitigation for vulnerable endangered species through the registration review process while formal endangered species consultation with the U.S. Fish and Wildlife Service and the National Marine Fisheries Service (the Services) is ongoing. This effort initiates one of four strategies EPA identified in its comprehensive 2022 Endangered Species Act (ESA) workplan that aims to improve protection for listed species meet the Agency’s ESA obligations.

Proposed Mitigations to Protect Specific Beetle, Tadpole Shrimp and Salamander Listed Species

EPA used its Biological Evaluation (BE) to identify three ″pilot″ species that are likely to be adversely affected (LAA) by methomyl use: the Valley Elderberry Longhorn Beetle, the Vernal Pool Tadpole Shrimp and the California Tiger Salamander. These pilot species have a high overlap with methomyl use, generally occurring in Northern California, specifically the Sacramento and San Joaquin River valleys. They are also representative of terrestrial invertebrates, aquatic invertebrates and amphibians that are at high risk of adverse effects.

An 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 is the unintentional harm or death of even one individual of a listed 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.

To mitigate potential risks to these species, the Agency developed mitigation measures that are expected to reduce their exposure to methomyl and their likelihood of being adversely affected. Proposed mitigation measures include prohibition of methomyl use in some areas, and measures that minimize methomyl spray drift and runoff in areas that extend over the pilot species’ range and critical habitat. EPA expects that undertaking these mitigations may prevent jeopardy to these species and adverse modification of the species’ critical habitat. Although these pilot species represent a small subset of the 1098 species and 281 critical habitats that received LAA determinations for methomyl, the proposed mitigations are intended to inform options for other listed species, as appropriate, that rise to the level of preliminary jeopardy or adverse modification due to methomyl use.

To learn more about this effort, including the methods used to identify these species and how EPA’s mitigation measures are expected to be protective, read pages 4-16 of EPA’s revised PID.

Proposed Mitigations to Protect Listed Salmon Species

Additionally, EPA is proposing mitigation measures to protect listed salmon species. In 2009, the National Marine Fisheries Service published a Biological Opinion that addresses effects of methomyl on Pacific salmonids. Now, in addition to the mitigations proposed in the 2020 methomyl PID, EPA is proposing mitigation measures to implement the 2009 Biological Opinion. These mitigations will help to reduce runoff, and they will establish a maximum annual application rate of methomyl that applicators cannot exceed.

Next Steps

The revised PID represents the next step in the registration review process for methomyl. EPA anticipates publishing the revised PID in the Federal Register the week of Oct. 3, 2022. Upon publication in the Federal Register, the public can comment on the revised PID for 60 days in the methomyl registration review docket EPA-HQ-OPP-2010-0751 at www.regulations.gov. After reviewing and considering comments, EPA will determine its next steps in the registration review process.

Background on Methomyl

Methomyl is a carbamate insecticide used to control foliage and soil-borne insect pests on a variety of food and feed crops, including field vegetables and orchard crops. The only non-agriculture use of methomyl is a fly bait product.

EPA has been evaluating methomyl as part of the registration review process. This review process requires the Agency to re-evaluate pesticides every 15 years to ensure that risk assessments and pesticide decisions reflect the best available science. Under ESA, the Agency must—in consultation with the Services—ensure that its registration review decisions do not jeopardize listed species or adversely modify their designated critical habitats.

In 2020, EPA released a PID for methomyl that proposed mitigation measures to ensure that use of methomyl products will not result in unreasonable adverse effects on the environment, consistent with EPA’s obligations under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). Following the release of the PID, the Agency released the BE for methomyl. The BE contains EPA’s effects determinations and analysis of the potential exposure of methomyl to listed species and their designated critical habitats.

Since EPA made a number of LAA determinations, EPA initiated consultation with the Services after the completion of the final BE in March 2021. During consultation, which is still ongoing, the Services may determine that additional measures are needed to avoid jeopardy to listed species and adverse modification of critical habitats from the use of methomyl. The Services may also identify measures to reduce the potential for take.