By Elizabeth Elkin | Updated on Jun 11, 2026 at 07:00 PM
A group of Senate Democrats is urging the US Department of Agriculture to step up efforts to tackle the screwworm outbreak in the US, including harnessing more sterile flies to combat the deadly cattle parasite.
Sen. Amy Klobuchar and 20 other senators wrote a letter to US Agriculture Secretary Brooke Rollins urging the USDA to take immediate further action to contain and respond to the New World screwworm outbreak. The Thursday letter acknowledged the US agency’s preliminary efforts, which included enhanced surveillance, sterile fly releases and coordination with animal health officials in Texas and New Mexico.
“These actions are critical first steps, but the evolving situation demands additional actions to ensure that the United States is adequately responding to the significance of this threat,” the letter said.
The USDA has come under criticism, mostly from Democrats, that the Trump administration’s deferred resignation program and the agency’s reorganization plans weakened its ability to detect and respond to the screwworm threat. A batch of cases in Texas calves over the past week marked the first US livestock outbreak in five decades. Rollins stands firm that the USDA has added employees to work on screwworm prevention and response since she took office.
Thursday’s letter calls for the USDA to expand and accelerate production of sterile flies, which are used to combat the spread of the parasite, and consider using the Defense Production Act to boost output of veterinary countermeasures and the flies.
Read More: What Is Screwworm and Why Is It a Cause for Concern?
The US has worked to expand its sterile fly distribution, including by opening a new dispersal facility in Texas. Still, there’s only one plant in North America producing 100 million flies a week — short of the 500 million flies a week used to push screwworm out of Texas in the last outbreak. Additional facilities in Mexico and Texas aren’t expected to come online until later this year and November 2027, respectively.
The letter also urged the USDA to use direct hiring authorities to expand animal and plant health inspection services and commit to not “disrupting” the outbreak response through permanent relocation orders.
The USDA has begun a sweeping restructuring , which includes moving workers out of Washington and closing regional offices. The agency lost a significant portion of its workforce over the last year and a half. APHIS, the agency that detects and responds to animal health events like screwworm, saw its frontline workforce in Texas cut by more than half, according to analysis by the National Sustainable Agriculture Coalition and Prospect Partners LLC.
Rollins has pushed back on suggestions that staff cuts could slow the agency’s response to the outbreak. The USDA added more than 100 full-time employees to work on screwworm over the last 15 months in preparation for the parasite’s arrival, she said Wednesday at a Senate hearing .