Resurgence of Screwworm Fly Raises Concerns in Texas

WHO:

The Texas Tribune - Texas Governor Greg Abbott expanded a statewide disaster declaration in response to the screwworm’s arrival in Texas.

The Texas Tribune - Abbott stated that the order authorizes the use of “all available resources of state government to respond to this disaster.”

Bloomberg Markets - A second case of the New World screwworm parasite has been confirmed in a Texas calf.

ABC News - Texas Governor Greg Abbott expressed concern that a new fly-breeding factory isn't expected to start work for more than a year to mitigate the New World screwworm fly infestation in Texas.

ABC News - Zavalas County Sheriff Eusevio Salinas stated that state officials were setting up several road checkpoints in the county to enforce the quarantine.

ABC News - U.S. Agriculture Secretary Brooke Rollins confirmed the infestation.

ABC News - Texas State Veterinarian Bud Dinges established a quarantine zone.

ABC News - Stephen Diebel, a Texas rancher and president of the Texas & Southwestern Cattle Raisers Association, expressed concerns about the infestation.

ABC News - Edward Burgess, a University of Florida entomologist, provided insights on the fly's reproduction and spread.

PBS - Agriculture Secretary Brooke Rollins stated there have been no other detections of the fly in the U.S.

WHAT:

The Texas Tribune - A second case of New World screwworm was confirmed in a one-month-old calf, found 5.6 miles away from the first case.

The Texas Tribune - The USDA has deployed mobile response teams and increased surveillance in the area following the detection of the second case.

The Texas Tribune - Abbott's order makes available all state personnel, including those from university systems, to expedite the shipment of sterile flies into Texas and the construction of a sterile fly facility.

Bloomberg Markets - The confirmation of a second case heightens fears of a broader outbreak that could impact the U.S. beef business.

Fast Company - The USDA is releasing additional sterile New World screwworms into the established zone to control the population.

Fast Company - The USDA has tested more than 58,000 fly samples, along with 19,000 wild animals.

Fast Company - The USDA is now dropping 4 million sterile flies twice a week and is also putting 4 million more a week in the ground as pupae.

Fast Company - The USDA has invested $21 million in a new fly-breeding facility in southern Mexico that is expected to start operations next month.

Fast Company - The USDA is spending $750 million to build a fly factory in southern Texas that can produce up to 300 million sterile flies a week, expected to begin operating next fall.

Fast Company - The USDA is now dropping 4 million sterile flies twice a week and is also putting 4 million more a week in the ground as pupae.

Fast Company - The USDA has invested $21 million in a new fly-breeding facility in southern Mexico that is expected to start operations next month.

Fast Company - The USDA is spending $750 million to build a fly factory in southern Texas that can produce up to 300 million sterile flies a week, expected to begin operating next fall.

Fast Company - The USDA is releasing additional sterile New World screwworms into the established zone to control the population.

Fast Company - The USDA has been dropping sterile flies in south Texas since February, releasing a total of 4 million flies twice a week, and it is also putting 4 million more a week in the ground as pupae.

Fast Company - The New World screwworm has been detected in Zavala County, Texas, specifically in a 3-week-old calf, with larvae found in the calf’s umbilical area.

Fast Company - The USDA has implemented quarantines, movement controls, and surveillance within a 20 km infested zone around the location of the infected calf.

ABC News - As of June 2, the parasite had sickened more than 171,700 animals and 2,000 people across Central America and Mexico, according to the U.S. Centers for Disease Control and Prevention.

ABC News - There have been 10 human deaths attributed to the parasite, as reported by the CDC.

ABC News - The USDA is now dropping 4 million sterile flies twice a week and is also putting 4 million more a week in the ground as pupae.

ABC News - The New World screwworm fly is threatening the $113 billion U.S. cattle industry for the first time in over 50 years.

ABC News - An infestation was confirmed in a single 3-week-old calf in La Pryor, Texas.

ABC News - The USDA has been dropping sterile flies in south Texas since February, releasing a total of 4 million flies twice a week.

PBS - The New World screwworm fly has only appeared in the U.S. three times since its eradication in the 1970s.

PBS - The USDA is spending $750 million to build a fly factory in southern Texas that can produce up to 300 million sterile flies a week.

WHERE:

The Texas Tribune - The second case was found in Zavala County, Texas, specifically 5.6 miles from the first case detected in La Pryor.

Bloomberg Markets - The second case was also confirmed in Texas.

Fast Company - The USDA has established a 20 km infested zone around the location where the infected calf was found in Zavala County, Texas.

Fast Company - Zavala County, Texas, has a population of around 9,200 and lies about 31 miles east of the Texas-Mexico border.

ABC News - The infestation was discovered in La Pryor, Texas, located about 100 miles southwest of San Antonio and 50 miles from the U.S.-Mexico border.

ABC News - A 12-mile quarantine zone was established covering much of Zavala County and a small part of neighboring Uvalde County.

WHEN:

The Texas Tribune - Abbott stated that the new sterile fly facility in Texas should be completed by May of next year, instead of November of next year.

Bloomberg Markets - The second case was confirmed on June 2, 2026.

Fast Company - The USDA's new fly-breeding facility in southern Mexico is expected to start operations next month.

ABC News - The USDA's new fly-breeding facility in southern Mexico is expected to start operations next month.

ABC News - The fly factory in southern Texas is expected to begin operating next fall.

ABC News - The USDA's new fly-breeding facility in southern Mexico is expected to start operations next month.

ABC News - The fly factory in southern Texas is expected to begin operating next fall.

ABC News - The most recent case of the screwworm fly in Texas was confirmed as the first since 1966.

ABC News - The fly was detected in Mexico late in 2024.

ABC News - The USDA's new fly-breeding facility in southern Mexico is expected to start operations next month.

PBS - The breeding facility in Mexico should be operating next month.

WHY:

The Texas Tribune - Abbott indicated that the screwworm is likely to spread over the course of the summer, necessitating a rapid response.

Bloomberg Markets - The emergence of the screwworm fly is raising concerns about its potential impact on the U.S. cattle industry.

ABC News - Agriculture Secretary Brooke Rollins stated that the Mexican government has not done enough to control animals moving within the country, a suggestion that Mexican authorities have rejected.

ABC News - Agriculture Secretary Brooke Rollins credited the closure of border entries to livestock in May 2025 with delaying the fly's arrival in Texas by a year.

ABC News - Agriculture Secretary Brooke Rollins stated that the case was in a 3-week-old calf in La Pryor, Texas, about 50 miles (80 kilometers) from the Mexico border.

ABC News - Federal and state officials aimed to keep the parasite from reaching Texas due to its significant cattle industry worth $17 billion.

ABC News - Agriculture officials noted that the fly does not infest food, which is a relief amid rising beef prices.

HOW:

The Texas Tribune - The USDA has dispersed more than 130 million sterile flies in Texas since January.

Wired - The U.S. currently has limited capacity to produce sterilized flies for combating the screwworm population.

Fast Company - The USDA is now dropping 4 million sterile flies twice a week and is also putting 4 million more a week in the ground as pupae.

Fast Company - The USDA is releasing additional sterile New World screwworms into the established zone to control the population.

ABC News - The USDA invested $21 million in a new fly-breeding facility in southern Mexico to increase the production of sterile flies.

ABC News - The USDA eradicated the pest in the past by breeding sterile male flies and dropping them from planes to mate with wild females.

ABC News - The USDA is implementing a strategy of releasing sterile flies to control the population of the screwworm fly.

PBS - Officials deployed 8,000 fly traps along the U.S.-Mexico border and tested more than 58,000 fly samples.

(UPDATED June 6, 2026 07:51 UTC)

Texas Governor Greg Abbott has expanded a statewide disaster declaration in response to the arrival of the New World screwworm, confirming a second case in a one-month-old calf found in Zavala County, just 5.6 miles from the first case in La Pryor. Abbott's order allows for the mobilization of all available state resources, including personnel from university systems, to expedite the shipment of sterile flies and the construction of a new sterile fly facility, which is now expected to be completed by May of next year. The USDA has already deployed mobile response teams and increased surveillance in the area, having dispersed over 130 million sterile flies in Texas since January to combat the potential spread of the screwworm this summer.

(UPDATED June 6, 2026 04:17 UTC)

A second case of the New World screwworm parasite has been confirmed in a Texas calf, raising concerns about a potential outbreak that could significantly impact the U.S. beef industry. This case, which was confirmed on June 2, 2026, highlights the challenges faced by the U.S. in producing enough sterilized flies to combat the screwworm population. As the emergence of this parasite continues to unfold, the cattle industry is on high alert for its possible repercussions.

(UPDATED June 5, 2026 23:19 UTC)

Texas Governor Greg Abbott has raised concerns about a new fly-breeding factory that won't begin operations for over a year, as efforts continue to combat the New World screwworm fly infestation in the state. In the meantime, the USDA is releasing additional sterile flies and has established a 20-kilometer infested zone around Zavala County, where an infected calf was discovered, while also testing over 58,000 fly samples and 19,000 wild animals. The USDA's new fly-breeding facility in southern Mexico is expected to start operations next month, and they are currently dropping 4 million sterile flies twice a week, along with an additional 4 million pupae weekly into the ground.

(UPDATED June 5, 2026 21:21 UTC)

The USDA is ramping up its efforts to control pests by releasing 4 million sterile flies twice a week in southern Texas, while also burying an additional 4 million as pupae. In a significant investment, the agency has committed $21 million to a new fly-breeding facility in southern Mexico, which is set to begin operations next month, and is spending $750 million to construct a fly factory in Zavala County, Texas, that will produce up to 300 million sterile flies weekly, with operations expected to start next fall. Zavala County, located about 31 miles east of the Texas-Mexico border, has a population of around 9,200 and is at the forefront of this pest control initiative.

(UPDATED June 5, 2026 19:32 UTC)

The USDA is ramping up efforts to combat a fly infestation by releasing four million sterile flies twice a week and introducing an additional four million as pupae. In a significant investment, the USDA has allocated $750 million to construct a fly factory in southern Texas, which is expected to produce up to 300 million sterile flies weekly and begin operations next fall. This initiative follows the closure of border entries to livestock in May 2025, which Agriculture Secretary Brooke Rollins noted delayed the fly's arrival in Texas by a year.

(UPDATED June 5, 2026 15:52 UTC)

The USDA is set to begin operations at a new fly-breeding facility in southern Mexico next month, while a similar facility in southern Texas is expected to start up next fall. To control the population of New World screwworms, the USDA has been releasing sterile flies in south Texas since February, with a total of 4 million flies being dropped twice a week, along with an additional 4 million pupae each week. This initiative follows a recent case of screwworm infestation found in a three-week-old calf in La Pryor, Texas, which is located about 50 miles from the Mexico border.

(UPDATED June 5, 2026 13:53 UTC)

The New World screwworm has been detected in Zavala County, Texas, after larvae were found in a three-week-old calf's umbilical area. In response, the USDA has implemented quarantines, movement controls, and surveillance within a 20-kilometer infested zone around the location of the infected calf. To help manage the situation, the USDA is also releasing additional sterile New World screwworms into the established zone.

(UPDATED June 5, 2026 10:26 UTC)

Zavalas County Sheriff Eusevio Salinas announced that state officials are setting up several road checkpoints in the county to enforce a quarantine due to a concerning outbreak. The U.S. Centers for Disease Control and Prevention reports that over 171,700 animals and 2,000 people have been sickened by a parasite across Central America and Mexico, with 10 human deaths attributed to it. In response, the USDA is investing $21 million in a new fly-breeding facility in southern Mexico, expected to start operations next month, while also dropping 4 million sterile flies twice a week to combat the spread of the parasite.

(UPDATED June 5, 2026 08:19 UTC)

U.S. Agriculture Secretary Brooke Rollins has confirmed a New World screwworm fly infestation in a three-week-old calf in La Pryor, Texas, marking the first occurrence of this pest in the U.S. in over 50 years. In response, Texas State Veterinarian Bud Dinges has established a 12-mile quarantine zone, while the USDA has been actively releasing sterile flies to combat the threat, having dropped a total of 4 million sterile flies since February. The USDA is also investing $750 million to build a fly factory in southern Texas, which is expected to produce up to 300 million sterile flies each week, with operations set to begin next month.