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EPA targets methomyl insecticide

Agency proposes measures to protect endangered species

by Britt E. Erickson
October 5, 2022 | A version of this story appeared in Volume 100, Issue 36


A California tiger salamander in the grass.
Credit: US Fish and Wildlife Service
The US Environmental Protection Agency is proposing restrictions on the insecticide methomyl to protect the California tiger salamander and other endangered species.

The US Environmental Protection Agency is proposing measures to reduce runoff and drift of the carbamate insecticide methomyl to protect vulnerable endangered species.

The changes would amend the agency’s registration review decision made in October 2020 under the administration of former president Donald J. Trump.

Methomyl is a carbamate insecticide used on field crops, vegetables, and orchards. It is also approved for use in a fly bait product.

The EPA is evaluating the risks of methomyl to human health and the environment as part of a registration review process that happens every 15 years. The agency completed an evaluation of the effects of methomyl on threatened and endangered species in March 2021, finding that the insecticide is likely to adversely affect more than 1,000 species. The agency is now consulting with the Fish and Wildlife Service and the National Marine Fisheries Service to determine what mitigation measures are needed to protect affected species.

While that consultation is ongoing, the EPA is proposing to implement measures to protect three endangered species that it determined are particularly vulnerable to methomyl: the elderberry longhorn beetle, vernal pool tadpole shrimp, and California tiger salamander.

The agency is also proposing measures to protect Pacific salmon. They include restricting the annual amount of methomyl that can be used in certain geographic areas that overlap with the salmon’s habitat.

Environmental groups welcome the proposed measures. “This is a small but important step forward for the EPA’s efforts to come to grips with the harms pesticides cause to endangered species,” Nathan Donley, environmental health science director at the Center for Biological Diversity, says in an emailed statement. “Getting these on-the-ground conservation measures to protect wildlife from methomyl is just common sense. Now the EPA needs to expand these efforts so that not one species is lost to extinction due to reckless pesticide use.”

The EPA is accepting public comments on the proposed decision until Dec. 5.



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