A flesh-eating cattle parasite spreads beyond Texas as new screwworm cases are found

Three more cases of the New World screwworm have been confirmed, including one outside the main cluster in Texas, demonstrating the difficulty of stopping a resurgent pest that could devastate the nation's cattle industry, the U.S. Department of Agriculture announced Monday.

The screwworm is actually a fly larva that eats living flesh instead of dead material. The flies lay their eggs in open wounds of animals like cattle, but wildlife, pets and occasionally even humans can be infested. The government has a program to breed sterile male flies and drop swarms of them from planes to mate with wild females, which kept screwworm contained at the southern end of Panama for decades.

So far, there are five confirmed cases: three calves and a goat in Texas and a dog from neighboring Lea County, New Mexico. The dog, which the USDA initially reported as a Texas case, lives in New Mexico and was reclassified as the first in that state. The animal's travel history is being investigated.

The first two screwworm cases were discovered last week in calves a few miles apart in south Texas. A case was announced Monday in a calf in La Salle County, southwest of San Antonio, and in a goat in Gillespie County, west of Austin.

Scientists expect new cases could pop up in the coming days and weeks, but it doesn't mean screwworm is spreading rapidly, said Edward Burgess, a University of Florida entomologist who studies the fly.

“When that first case is seen, everyone is being vigilant and their eyes are on it more intensely,” Burgess said. “And when you are looking for something, you are more likely to see it.”

Screwworm gets its name from the maggots’ habit of burrowing — or screwing — into a wound, according to the USDA.

The agency and the U.S. cattle industry have been racing to prevent an outbreak since screwworm was detected in Mexico late in 2024. The USDA has been dropping sterile flies in south Texas since February, and is working to both increase sterile fly production in plants outside the U.S. and build a $750 million fly factory in Texas.

So far, screwworm's reappearance hasn’t greatly affected beef prices, which are already near record levels because there are fewer cows in the United States. Although the parasite attacks live cattle, it does not infest meat or fruit. There are also a dozen government-approved medications to treat livestock.

Canada temporarily stopped importing cattle, horses or other livestock from Texas on Friday. The parasites prefer humid areas where temperatures are at least 77 F (25 C), making them more of a summer problem up north.

Burgess said the long-term solution — breeding sterile male flies — is months away. Since wild female flies mate just once, if that encounter is with a sterile male, outbreaks can eventually be halted as the flies die out.

The goal is to have enough sterile flies to stop the pests from returning in 2027 after the winter kills off most of them, USDA Secretary Brooke Rollins said at a news conference at the U.S. Livestock Insects Research Laboratory in Kerrville, Texas.

Scientists are also working on ways to sterilize only male flies to make the program even more effective.

Texas officials encouraged ranchers to keep a close eye on their herds and local wildlife. There's now a 24-hour screwworm hotline and a website and map for reported cases.

“This is a highly treatable condition if you act on it immediately,” Republican Gov. Greg Abbott said.

However, Texas Agriculture Commissioner Sid Miller — who lost the recent Republican primary to a candidate backed by Abbott — said the federal response will take too long and risks crippling the cattle industry.

Instead, he says a poison bait could eliminate the screwworm problem in a few months, even if the USDA and other experts say the bait hasn’t been proven effective and could poison other flies, animals and even humans.

“What the hell is a good fly?” Miller said in an interview.

This story has been updated to reflect that the USDA revised the dog screwworm case to New Mexico, not Texas as the agency initially reported, and to correct the spelling of Kerrville.

Associated Press writer Scott McFetridge in Des Moines, Iowa, contributed to this report.

U.S. Agriculture Secretary Brooke Rollins, center, holds a news conference with ranchers, researchers and officials at the Knipling-Bushland U.S. Livestock Insects Research Laboratory in Kerrville, Texas, Monday, June 8, 2026. (AP Photo/Eric Gay)

A ranchers arrivse for a news conference with U.S. Agriculture Secretary Brooke Rollins at the Knipling-Bushland U.S. Livestock Insects Research Laboratory in Kerrville, Texas, Monday, June 8, 2026. (AP Photo/Eric Gay)

FILE - A test container of dyed fly pupae are displayed at a Domestic New World Screwworm Sterile Fly Production Facility to combat the northward spread of NWS and protect American livestock, in Edinburg, Texas, Feb. 9, 2026. (AP Photo/Eric Gay, File)

FILE - An adult New World screwworm fly sits in this undated photo. (Denise Bonilla/U.S. Department of Agriculture via AP)

Hilary Knight is heading to the PWHL’s expansion team in Detroit as part of a sign-and-trade deal involving one of women's hockey’s most recognized stars, a person with knowledge of the deal told The Associated Press on Monday.

The person said Knight will first sign a foundational contract with Las Vegas as part of Phase 2 of the league’s expansion signing process. Las Vegas in turn has reached an agreement to trade Knight to Detroit for the team’s first-round pick in the draft next week, the person added.

The person spoke to the AP on condition of anonymity because they were not authorized to reveal the trade. The deal won’t become official until the PWHL’s trade freeze lifts on June 16, a day before the draft.

The 36-year-old Knight is a five-time U.S. Olympian and one of the most decorated players in her sport. She is coming off captaining Team USA to a gold-medal victory at the Milan Cortina Games in February, in which Knight deflected in the championship game-tying goal late in the third period of a 2-1 overtime win against Canada.

Though Knight said the Olympics in Milan would be her last, she planned on continuing her pro career.

Knight is on the move for a second straight PWHL offseason. After spending her first two PWHL seasons in Boston, she left the Fleet to sign with the expansion Seattle Torrent to be closer to her offseason home in Idaho.

Now, it’ll be the Chicago-area town where she grew up that she’s closer to.

As much as Knight and the Torrent would have preferred she remain in Seattle, the team under the expansion rules was restricted to protecting three players. The Torrent chose to protect forward Alex Carpenter, defender Anna Wilgren and goalie Hannah Murphy.

Knight at least gets the benefit of signing a foundational offer, which guarantees her making at least $100,000 per season. She made $106,090 last year.

Each of the PWHL’s four expansion teams were allowed one foundational contract offer. Las Vegas still had its foundational slot open, while Detroit used its offer to sign Toronto forward Daryl Watts last week.

Las Vegas, meanwhile, lands an additional first-round pick in a draft class stocked with young talent and led by five U.S. national team members, including defender Caroline Harvey and defender/forward Laila Edwards. The PWHL has yet to set the draft order, with the exception of Vancouver picking first.

Knight counts toward one of the five players Las Vegas must add in this expansion phase, which closes on Monday. The team has two more slots open after signing Minnesota defenders Mae Batherson and Kendall Cooper on Saturday.

In Detroit, Knight joins a team that already features three U.S. gold medal-winning teammates in forwards Britta Curl-Salemme, Hannah Bilka and defender Cayla Barnes, who were signed in the expansion process. She also is reunited with newly hired Detroit coach Josh Sciba, who was an assistant on the U.S. Olympic team.

And Knight joins a team headed by one of women's hockey's trailblazers in GM Manon Rheaume. The 54-year-old Rheaume was a goaltender, and the first woman to appear in an exhibition game of any of North America’s four major sports.

Earlier in the day, Detroit filled its fifth expansion spot by signing Toronto forward Jesse Compher to a three-year contract. Compher won a silver medal representing the U.S. at the 2022 Beijing Games.

Knight finished last season with five goals and 14 points in 22 games, while missing the final two months of the season with a lower-body injury. A year earlier, she finished tied for the league lead with 29 points (15 goals, 14 assists). Overall, she ranks 12th in the PWHL with 54 career points (26 goals, 28 assists) in 76 games.

The trade caps an eventful stretch for Knight. A day before winning gold, she became engaged to American speedskater Brittany Bowe. Her goal against Canada was her 15th and 33rd point of her Olympic career, setting U.S. records for both categories.

In 2024, Knight was the International Ice Hockey Federation's female player of the year. She has won two Olympic gold and three silver medals since making her Team USA debut at the 2007 world championships. She has won 10 gold medals at worlds and holds the career tournament records for goals (67), assists (53) and points (120).

AP women’s hockey: https://apnews.com/hub/womens-hockey

FILE - Seattle Torrent's Hilary Knight (21) waits for a face off against the Vancouver Goldeneyes during the second period of a PWHL hockey game in Vancouver, on Tuesday, April 14, 2026. (Ethan Cairns/The Canadian Press via AP,File)