Federal organization prosecuted for using pesticides on courses

Two environmental groups are suing the Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) over its use of pesticides to control outbreaks of Mormon grasshoppers and locusts in western states.

The court case filed in Oregon district court by the Xerces Society and the Center for Biological Diversity claims that APHIS ignored its congressional mandate for a “holistic” approach to grasshopper control and instead focused almost solely on the use of pesticides.

Drought can exacerbate grasshopper population growth because naturally occurring insect-toxic fungi do not grow as well in dry conditions.

Left alone, grasshoppers could decimate pasture food for non-native livestock and can also have detrimental effects on crops like barley and wheat. More than 400 grasshopper species exist in western rangelands, but only a dozen are considered pests, according to APHIS.

The agency monitors grasshoppers in 17 western states, and when it deems there’s an outbreak or is asked to intervene by stakeholders like the U.S. Forest Service or adjacent landowners, it may apply pesticide to kill insects.

“It stops the insect from molting and you end up with insects that die,” says Michael Perrella, an entomologist and dean of the College of Agricultural and Life Sciences at the University of Idaho.

APHIS Documentation shows that he primarily uses a chemical called diflubenzuron to control grasshoppers. Parrella said it was an effective product that had been used for decades, with no specific harmful effects on fully grown mammals or insects.

But, he said, “there is a kind of risk that you take every time you spray pesticide; you need to balance the risk with the potential benefit.

Parrella does not know the APHIS Grasshopper Control Program but said he would assume the agency did their due diligence. He cited a large amount of data from decades of using diflubenzuron on the East Coast to treat gypsy moth infestations.

The lawsuit argues that APHIS has not checked all the boxes since it re-authorized its course pesticide program in 2019.

“The Environmental Impact Statement (“EIS”) prepared pursuant to the National Environmental Policy Act (“NEPA”) does not even disclose the locations of past pesticide applications. EIA 2019 make any meaningful attempt to examine how the APHIS program combines with actions taken by other actors – private, state, tribal, and federal – to affect native pollinators, other invertebrates, or dependent animals and plants of these invertebrates for food or pollination,” the suit reads.

APHIS reports that it directly treated more than 800,000 acres of rangeland for grasshoppers in 2021, in the Mountain West states from Montana to New Mexico. The application process deals with alternating strips of land, which means that the total area processed is considered to be 1.6 million acres.

A heat map Grasshopper density data show that the insects were most populated last year in eastern Oregon and Montana.

Parrella said that when applied correctly, chemicals targeting invertebrates during molting do not affect fully grown insects. Dimilin is the trade name for the pesticide diflubenzuron.

“But there are fears that pollinators will pick up dimilin residue, bring it back either to the hive or to where they raise young,” he said.

Advocates say eliminating grasshoppers also harms an essential food source for native range birds and protected species like sage-grouse.

“APHIS is out of control, spraying deadly poisons on biodiversity hotspots like Oregon’s Malheur National Wildlife Refuge, which is visited each year by tens of thousands of people eager to see the incredible diversity birds and wildlife there,” said Lori Ann Burd, environmental manager. director of health at the Center for Biological Diversity in a press release. “It is time that this outlaw branch of the USDA be held accountable for its active contribution to the escalation of the extinction crisis.”

Parrella doesn’t think any treatment can achieve its goals without side effects, but he said there are biologic alternatives to dimilin.

The lawsuit alleges that the environmental impact statement under which the rangeland pesticide program operates is incomplete and violates environmental protection laws.

A spokesperson for APHIS said the agency would not comment on ongoing litigation.

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Virginia S. Braud