LINCOLN, Neb. (DTN) -- The Center for Biological Diversity will sue the U.S. Fish and Wildlife Service near the end of April if the agency doesn't respond to a 2019 petition to restrict pesticide use in critical habitats, the group said in a letter to the agency on Monday.

The Center filed a petition with USFWS on Jan. 7, 2019, asking for pesticide restrictions in habitats for threatened and endangered species. The Biden administration's EPA has been conducting Endangered Species Act reviews on agriculture chemicals.

"An assessment of the EPA's own biological evaluations illustrates the substantial harm that pesticides continue to cause to threatened and endangered species and their designated critical habitats," the Center for Biological Diversity said in its intent-to-sue letter to USFWS.

"By compiling the information in the biological evaluations for chlorpyrifos, diazinon, malathion, carbaryl, methomyl, glyphosate, atrazine, simazine, imidacloprid, thiamethoxam, clothianidin and sulfoxaflor, it is readily apparent just how common it is for pesticides to harm critical habitat -- in fact, it is the norm, not the exception that pesticides harm critical habitat."

The center stated it identified 42 threatened and endangered species that would benefit most from protecting critical habitats.

"Of these 42 species, the EPA determined that the critical habitats are likely adversely affected by eight or more of the 12 pesticides," the letter said, "with the vast majority (35 of 42) being likely to be adversely affected by 11 or more of these 12 pesticides. Without action to prohibit the use of pesticides within critical habitat, these species are at particular risk of extinction from adverse modification and destruction of their habitat."

Since it has been more than four years since the center filed its petition, the group said it will sue within 30 days unless USFWS initiates a rulemaking or issues a "substantive response" to the petition.

That original petition was filed, the group said, because of the EPA's "systemic failure to address the harm that pesticides cause to threatened and endangered species."

The center said pesticides represent a "substantial or even primary threat" to hundreds of endangered species.

According to USFWS's recovery plans for more than 250 threatened and endangered species, pesticides are listed as known threats to their recovery, the center stated.

"While the EPA has taken some important steps in the last two years to begin addressing its historic non-compliance with the Endangered Species Act, the conservation status of many threatened and endangered species continues to decline," the group said in the letter, "as little on-the-ground conservation measures have actually been deployed to date."

The center stated that in an "effort to avoid litigation," it identified about 40 "highly imperiled, narrowly endemic species" that would receive the "greatest benefit" from a prohibition on the use of pesticides within critical habitat.

"Should the service wish to avoid litigation by developing a plan to implement restrictions on the use of pesticides within these critical habitat designations, the center would defer litigation at this time," the letter said.

Read more on DTN:

"Cattle Groups Fight Addition of Lesser Prairie Chicken to Endangered Species List," https://www.dtnpf.com/…

"What the Endangered Species Act Means for Ag Pesticide Use," https://www.dtnpf.com/…

"EPA Tackles Endangered Species Duties," https://www.dtnpf.com/…

"EPA Proposes New Approach for Pesticides," https://www.dtnpf.com/…

Todd Neeley can be reached at todd.neeley@dtn.com

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