USDA confirms presence of New World Screwworm in the United States

2 days ago
2 min read

Officials stress two key messages: 1) This is not a food safety crisis, and 2) the pest spreads with animals, not by flies traveling long distances on their own.

Source: USDA news release

WASHINGTON, D.C., June 3, 2026—The U.S. Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service (APHIS) confirmed the detection of a New World screwworm (NWS) in a bovine in Zavala County, Texas. NWS is a serious pest that affects livestock, pets, wildlife, and less commonly, people and birds. NWS larvae (maggots) burrow into the flesh of living animals, causing serious damage to livestock and economic losses.

The affected animal is a 3-week-old calf and larvae were identified in its umbilical area. To date, there have been no further detections.

File photo. Image credit NFWF — *File photo.* ***Image credit NFWF***

“All models showed New World Screwworm entering the country in 2025; however, thanks to the hard work across the entire Trump administration and our industry, state, and local partners, we were able to buy time for this moment. Protecting our livestock industry is a national security issue of the utmost importance, and USDA is wasting no time in taking action,” said Dudley Hoskins, Under Secretary for Marketing and Regulatory Programs. “USDA invested heavily in the tools needed to eliminate NWS ever since cases started increasing in Central America and Mexico. The United States has defeated this pest before, and we will do it again.”

USDA and Texas officials are taking immediate action to contain and eradicate NWS from the United States, following the strategies and actions outlined in the NWS Response Playbook (884.59 KB). This includes:

Forming a unified Incident Command Team with the Texas Animal Health Commission and deploying response personnel to the area;
Establishing a 20 km infested zone around the detection and implementing quarantines, movement controls, and surveillance in this area;
Expediting targeted release of sterile NWS flies (423.58 KB) by immediately deploying ground release chambers in the area, in addition to the 4 million sterile flies per week already being released aerially in the area;
Increasing trapping for NWS flies along the border and just outside of the dispersal area;
Implementing NWS surveillance and management strategies in wildlife; and
Conducting targeted outreach in the local area.
Additionally, USDA’s National Veterinary Stockpile stands ready to assist and will provide resources including treatments, equipment, and logistics support the response as needed.