A case of New World butcherworm has been confirmed in south Texas, the U.S. Department of Agriculture announced Wednesday evening. This is the first detected violation of the U.S.-Mexico border by authorities. voracious carnivorous flieswho have have made their way across Central America in recent years.
In a post on social media Wednesday afternoonthe USDA revealed that a sample from Texas was sent to the National Veterinary Services Laboratories (NVSL) in Ames, Iowa, for confirmatory testing for alfalfa infection. Agriculture Secretary Brooke Rollins later released that tests had confirmed the infectionwhich was found in a three-week-old calf in Zavala County, Texas.
Rumors regarding the detection of a beef worm had already multiplied this week, shaking the American cattle industry.
Although many animals, including humans, can fall victim to the parasite, the screwworm is particularly dangerous to livestock. Female dung worms lay hundreds of eggs in the wounds and openings of warm-blooded creatures, allowing their larvae to feast on living animals, causing deep, festering, and potentially fatal wounds. Although the butcher caterpillar was once endemic to the United States, it was eradicated in the 1960s through a control effort that lasted several years. The USDA believes that preventing dung worms from entering the United States has saved the livestock industry $900 million each year.
But the fly managed to evade control efforts in Central America and came closer. On May 28, a case was discovered 25 miles from the border in a five-year-old goat in Coahuila, Mexico, according to the USDA. This case is one of several detected in recent days, including a case in a calf just 39 miles from the border, also in Coahuila.
Disputed detections
In a media call Tuesday, Agriculture Secretary Brooke Rollins said, “There is no doubt that this is a very, very serious threat to our livestock. » But she also disputed claims that the fly is closer or even already in the United States.
On Monday, State Rep. Don McLaughlin claimed on social media that a case of butcher worms had been discovered just a mile from the Texas borderthat Rollins and the USDA refused.
“When false information is disseminated, it causes great panic” Rollins said Tuesday, according to the Texas Tribune. “And rightly so, especially if it comes from elected officials and the media.”
Wednesday, Reuters reported that McLaughlin suspected the fly was now there. He said samples taken Tuesday from two calves from a ranch in La Pryor, Texas — which is in Zavala County, where butcher worm infection was confirmed — were being tested for possible butcher worm infections. An infection apparently occurred in a wound in the umbilical cord of one of the calves. McLaughlin said he had seen pictures and videos of the animals and the larvae seen looked like butcher worm larvae.
Reuters saw one of the photos, which it said showed “several screwworm-like larvae inside a bloody circular wound on an animal,” but said it “could not immediately verify the photo.”
“At this point, it is not confirmed to be the New World butcher worm,” McLaughlin told the outlet earlier Wednesday. “It looks like it, but it’s not confirmed.”
With the findings now confirmed, the USDA said in a press release Wednesday evening that it is establishing a “unified incident command team” with the Texas Animal Health Commission and sending response personnel to the region. It is also establishing a 20-kilometer zone around the detected infection for quarantine, movement restrictions and increased surveillance and fly trapping.
The return of the mud worm
Butcher worms were eradicated in the United States in the 1960s as part of a concerted effort to wipe out their population. This is done through aerial bombardments of sterile male flies, which are the most effective weapon against parasites. The mass release of failed stallions pushes aside fertile males, preventing them from mating with females, who typically mate only once.
Using this method, called Sterile Insect Technique, flies have been eradicated not only from the United States but from all of Central America. They were declared eradicated from Panama in 2006.
Until recently, the meat worm population was kept at bay via a biological barrier along the Darién Gap on the border of Panama and Colombia. The USDA partnered with Panamanian authorities to build a remote sterile fly production facility to regularly release sterile flies and maintain the line. But in 2022, the barrier was breached and the flies have been buzzing relentlessly north ever since.
In response, the United States has increased surveillance and trapping efforts in Texas. It is also building a $750 million sterile fly production facility in South Texas. The USDA says it disperses 100 million sterile insects per week in Mexico and along the U.S.-Mexico border to prevent the flies from advancing further.
In Wednesday evening’s press release, the USDA announced that it would release sterile flies via ground release chambers in the area around the detection. This is in addition to the 4 million flies already released from the air in the region this week.
“The United States has defeated this pest before, and we will do it again,” Dudley Hoskins, USDA undersecretary for marketing and regulatory programs, wrote in the press release.
This story was originally published on Ars Technica.
