Latest news with #NewWorldScrewworms
Yahoo
15-07-2025
- Science
- Yahoo
The US has a plan to breed millions of flies and drop them from planes. Here's why
Hundreds of millions of flies dropping from planes in the sky might sound like a horrible nightmare, but experts say such a swarm could be the livestock industry's best defense against a flesh-eating threat poised to invade the southwestern border of the United States. An outbreak of New World screwworms — the larval form of a type of fly that's known to nest in the wounds of warm-blooded animals and slowly eat them alive — has been spreading across Central America since early 2023, with infestations recorded in Panama, Costa Rica, Nicaragua, Honduras, Guatemala, Belize and El Salvador. Most Central American countries hadn't seen an outbreak in 20 years. The fly reached southern Mexico in November, sparking concern among US agricultural industry officials and triggering the closure of several border-area cattle, horse and bison trading ports. It wouldn't be the first time the US has had to battle these invasive bugs. The nation mostly eradicated the New World screwworm populations in the 1960s and 1970s by breeding sterilized males of the species and dispersing them from planes to mate with wild, female flies. The strategy — essentially fighting flies with flies — slowly degraded the insects' populations by preventing them from laying more eggs. Now, as the insects continue to spread north officials are hoping the approach could work again. However, today only one facility in Panama breeds sterilized New World screwworms for dispersal, and hundreds of millions more sterile flies are needed to slow the outbreak, according to a June 17 letter from 80 US lawmakers. The next day, the US Department of Agriculture announced plans to open a 'fly factory' in a yet to be determined town near the Texas-Mexico border. But the process of defeating the screwworm may not be quick — or inexpensive. New World screwworms are the parasitic larva of a metallic blue blow fly species called Cochliomyia hominivorax. Unlike all other blow flies native to the Western Hemisphere, the New World screwworm feeds on the flesh of living animals, rather than dead ones, said Dr. Phillip Kaufman, a professor and head of the department of entomology at Texas A&M University. The flesh-eating maggots go for most warm-blooded animals, including horses and have also been known to infect domestic pets and even humans in rare cases, Kaufman said. 'After mating, the female fly finds a living host, lands on its wound, and will lay up to 200 to 300 eggs,' Kaufman explained. 'After 12 to 24 hours, those eggs all hatch, and they immediately start burrowing and feeding on the tissue of that animal, causing very, very large wounds to form.' After the larvae feed on the tissue with their sharp mouth hooks for several days, they drop from the animal and burrow into the ground to emerge later as fully grown adult flies, according to Thomas Lansford, the deputy executive director and assistant state veterinarian for the Texas Animal Health Commission. Since the outbreak began in 2023, there have been more than 90,000 New World screwworm infestations reported, according to a USDA spokesperson. Treatment for infested cattle often involves cleaning, antiseptic treatment and coverings for the wounds, Lansford said. If left untreated, the flies can kill an animal in a matter of one to two weeks and spread to others, posing a threat to the livelihood of ranchers. 'It's a daily chore to provide those inspections to our livestock, just to make sure they're not infested,' said Stephen Diebel, a rancher and the first vice president of the Texas & Southwestern Cattle Raisers Association. 'We know the incredible economic impact an infestation would cause.' There are no known vaccinations or effective repellant methods to prevent infestation, Diebel said. Instead, during warmer months, ranchers should avoid branding, tagging and other procedures that create potential entry points for the screwworms in livestock, he recommended. The tropical fly is less active in the winter. While regional cattle trading is thought to be a major way the fly populations travel, Diebel said infestations can also affect wildlife such as deer, birds and rodents, making surveillance of the parasite's spread even more challenging. Just like a caterpillar goes into a cocoon before becoming a butterfly, the New World screwworm becomes a black, pill-sized pupa before emerging as an adult fly, Kaufman explained. In a sterile fly production facility, the pupae are subjected to high-energy gamma rays that break down the DNA of the males, damaging their sex chromosomes, according to the USDA. The result: impotent adult flies that cause female mates to lay unfertilized eggs. The amount of radiation the male flies are exposed to does not pose a danger to animals or humans, according to the USDA. But since the female flies only mate one time in their short, 20-day lifespan, once populations are exposed to sterile males, the populations die out over the course of months or years, depending on the size of the outbreak. While it is unclear how dispersal would work in the US in the event of an outbreak, Kaufman said the adult flies are typically loaded into temperature-controlled containers and dropped from planes. However, there's no need to panic about the fly drops coming to a suburb near you, he said — they usually target sparsely populated rural areas, since the flies have no interest in urban environments. At the Panama–United States Commission for the Eradication and Prevention of Screwworm Infestation in Livestock (COPEG) facility, about 100 million sterilized flies are produced and dispersed aerially in affected regions each week. Currently, the dispersal efforts have been focused in the southern regions of Mexico and throughout Central America, where cases of infestation have been reported, according to COPEG's website. The new US dispersal facility is expected to be located at the Moore Air Base in Hidalgo County, Texas, and to cost $8.5 million, per the release. The location and price tag of the production facility, or the 'fly factory' itself, has not been revealed, but lawmakers estimate it could cost around $300 million. In addition to the new sterile fly facilities, the USDA also announced $21 million plans to renovate an old fly factory in Mexico by late 2025. While the plans are expensive, it's a price worth paying to save the multibillion-dollar livestock industry, Diebel said. 'When you offset the $300 million to the $10 billion of economic impact these flies would have, it's an easy trade-off to understand,' Diebel said. 'Having (a domestic production facility) here is super important … to control the distribution of those sterile flies more efficiently.' Shortly after the June 18 announcement, the USDA shared plans to begin reopening livestock trading ports in Arizona, Texas and New Mexico that closed last year, citing 'good progress' in surveillance and sterile fly dispersal efforts throughout Mexico. COPEG did not immediately respond to request for comment on further details about the current progress of the US dispersal initiatives. Editor's Note: This story has been updated to reflect the latest screwworm infestation numbers from COPEG.
Yahoo
11-07-2025
- Science
- Yahoo
The US has a plan to breed millions of flies and drop them from planes. Here's why
Hundreds of millions of flies dropping from planes in the sky might sound like a horrible nightmare, but experts say such a swarm could be the livestock industry's best defense against a flesh-eating threat poised to invade the southwestern border of the United States. An outbreak of New World screwworms — the larval form of a type of fly that's known to nest in the wounds of warm-blooded animals and slowly eat them alive — has been spreading across Central America since early 2023, with infestations recorded in Panama, Costa Rica, Nicaragua, Honduras, Guatemala, Belize and El Salvador. Most Central American countries hadn't seen an outbreak in 20 years. The fly reached southern Mexico in November, sparking concern among US agricultural industry officials and triggering the closure of several border-area cattle, horse and bison trading ports. It wouldn't be the first time the US has had to battle these invasive bugs. The nation mostly eradicated the New World screwworm populations in the 1960s and 1970s by breeding sterilized males of the species and dispersing them from planes to mate with wild, female flies. The strategy — essentially fighting flies with flies — slowly degraded the insects' populations by preventing them from laying more eggs. Now, as the insects continue to spread north officials are hoping the approach could work again. However, today only one facility in Panama breeds sterilized New World screwworms for dispersal, and hundreds of millions more sterile flies are needed to slow the outbreak, according to a June 17 letter from 80 US lawmakers. The next day, the US Department of Agriculture announced plans to open a 'fly factory' in a yet to be determined town near the Texas-Mexico border. But the process of defeating the screwworm may not be quick — or inexpensive. New World screwworms are the parasitic larva of a metallic blue blow fly species called Cochliomyia hominivorax. Unlike all other blow flies native to the Western Hemisphere, the New World screwworm feeds on the flesh of living animals, rather than dead ones, said Dr. Phillip Kaufman, a professor and head of the department of entomology at Texas A&M University. The flesh-eating maggots go for most warm-blooded animals, including horses and have also been known to infect domestic pets and even humans in rare cases, Kaufman said. 'After mating, the female fly finds a living host, lands on its wound, and will lay up to 200 to 300 eggs,' Kaufman explained. 'After 12 to 24 hours, those eggs all hatch, and they immediately start burrowing and feeding on the tissue of that animal, causing very, very large wounds to form.' After the larvae feed on the tissue with their sharp mouth hooks for several days, they drop from the animal and burrow into the ground to emerge later as fully grown adult flies, according to Thomas Lansford, the deputy executive director and assistant state veterinarian for the Texas Animal Health Commission. Since the outbreak began in 2023, there have been more than 35,000 New World screwworm infestations reported, according to statistics listed on the Panama–United States Commission for the Eradication and Prevention of Screwworm Infestation in Livestock (COPEG) website. Of those cases, cows make up about 83% of the affected animal species. Treatment for infested cattle often involves cleaning, antiseptic treatment and coverings for the wounds, Lansford said. If left untreated, the flies can kill an animal in a matter of one to two weeks and spread to others, posing a threat to the livelihood of ranchers. 'It's a daily chore to provide those inspections to our livestock, just to make sure they're not infested,' said Stephen Diebel, a rancher and the first vice president of the Texas & Southwestern Cattle Raisers Association. 'We know the incredible economic impact an infestation would cause.' There are no known vaccinations or effective repellant methods to prevent infestation, Diebel said. Instead, during warmer months, ranchers should avoid branding, tagging and other procedures that create potential entry points for the screwworms in livestock, he recommended. The tropical fly is less active in the winter. While regional cattle trading is thought to be a major way the fly populations travel, Diebel said infestations can also affect wildlife such as deer, birds and rodents, making surveillance of the parasite's spread even more challenging. Just like a caterpillar goes into a cocoon before becoming a butterfly, the New World screwworm becomes a black, pill-sized pupa before emerging as an adult fly, Kaufman explained. In a sterile fly production facility, the pupae are subjected to high-energy gamma rays that break down the DNA of the males, damaging their sex chromosomes, according to the USDA. The result: impotent adult flies that cause female mates to lay unfertilized eggs. The amount of radiation the male flies are exposed to does not pose a danger to animals or humans, according to the USDA. But since the female flies only mate one time in their short, 20-day lifespan, once populations are exposed to sterile males, the populations die out over the course of months or years, depending on the size of the outbreak. While it is unclear how dispersal would work in the US in the event of an outbreak, Kaufman said the adult flies are typically loaded into temperature-controlled containers and dropped from planes. However, there's no need to panic about the fly drops coming to a suburb near you, he said — they usually target sparsely populated rural areas, since the flies have no interest in urban environments. At the COPEG facility, about 100 million sterilized flies are produced and dispersed aerially in affected regions each week. Currently, the dispersal efforts have been focused in the southern regions of Mexico and throughout Central America, where cases of infestation have been reported, according to COPEG's website. The new US dispersal facility is expected to be located at the Moore Air Base in Hidalgo County, Texas, and to cost $8.5 million, per the release. The location and price tag of the production facility, or the 'fly factory' itself, has not been revealed, but lawmakers estimate it could cost around $300 million. In addition to the new sterile fly facilities, the USDA also announced $21 million plans to renovate an old fly factory in Mexico by late 2025. While the plans are expensive, it's a price worth paying to save the multibillion-dollar livestock industry, Diebel said. 'When you offset the $300 million to the $10 billion of economic impact these flies would have, it's an easy trade-off to understand,' Diebel said. 'Having (a domestic production facility) here is super important … to control the distribution of those sterile flies more efficiently.' Shortly after the June 18 announcement, the USDA shared plans to begin reopening livestock trading ports in Arizona, Texas and New Mexico that closed last year, citing 'good progress' in surveillance and sterile fly dispersal efforts throughout Mexico. COPEG did not immediately respond to request for comment on further details about the current progress of the US dispersal initiatives.
Yahoo
13-06-2025
- Politics
- Yahoo
Texas ranchers brace for possible screwworm threat
SAN ANGELO, Texas (Concho Valley Homepage) — On ranches in South Texas, the mood is tense as word is reaching ranchers about the spreading of New World Screwworms. These are flesh-eating parasites that target warm-blooded animals. While there are no reports of screwworms having crossed the border into Texas, many are recalling a procedure of using sterile male screwworm flies that eradicated this problem in the U.S. several decades ago. 'Screwworms have been in the United States before, back in the 50s, 60s and 70s. We controlled those outbreaks at those times with sterile male screwworm flies,' Charlie Christenson at Producers Livestock Auction said. Christenson said the way to get ahead of these screwworms spreading into Texas is by having the means to produce these sterile flies. He says the effects of screwworm infestations on animals can be dire. 'They leave larvae on an open wound on an animal, and that larvae turns into a screwworm that basically feeds on living flesh, which is the difference between it and a maggot,' Christenson said. Knowing that screwworms could cross from Mexico into Texas, Texas Representative Tony Gonzales in Washington, D.C. created legislation called the 'STOP Screwworms Act' to allocate funding to create the exact facility needed to produce sterile flies. 'It's very much focused on creating a facility that will sterilize these flies to stop the spreading of screwworms…we have to stop relying on foreign countries to do our work and to me it makes a whole lot of sense if this facility is right here in Texas…right here in the United States.' Christenson said he is hopeful for this new legislation because those with cattle are not the only ones who can be impacted by screwworms. 'It makes cattleman and sheep people…everybody that has wildlife…the deer people are nervous about it because of the open wound,' Christenson said. USDA officials are monitoring the border as we await action from this new piece of legislation. For now, these ranchers say they'll stay alert and hope this sterile fly facility comes before the screwworms do. Copyright 2025 Nexstar Media, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.
Yahoo
12-05-2025
- Health
- Yahoo
What is the New World Screwworm? Flesh-eating parasite is impacting cattle imports
The United States is halting imports of livestock from Mexico to protect U.S. livestock from a flesh-eating parasite called the New World Screwworm. The New World Screwworm, or the NWS for short, is a parasitic fly that was eradicated in the U.S. in the 1960s. The fly gets its name for how its maggots feed on an animal by burrowing, or screwing, into an open wound, creating "extension damage by tearing at the hosts' tissue with sharp mouth hooks," the Animal and Plant Health Inspection Service states. The import suspension was announced by U.S. Department of Agriculture Secretary Brooke Rollins on Sunday, May 11, following a detection of the flies in remote farms about 700 miles south of the Mexico-U.S. border. The suspension will be reevaluated on a "month-by-month basis," a USDA statement reads. Here's what to know about the New World Screwworm, including its past presence in the U.S. New World Screwworm: Parasite threat forces US to halt cattle imports from Mexico The New World Screwworm is a parasitic fly, about the size of a common housefly. They have orange eyes, a metallic blue or green body and three dark stripes along their backs, according to the Animal and Plant Health Inspection Service. The fly gets its name for the behavior of its maggots, which burrow, or screw, into an animal's open wound, feeding as they go. The New World Screwworm has sharp mouth hooks, allowing them to burrow deep into an animal's flesh. New World Screwworms can infest livestock, pets, wildlife, birds and in rare cases, people. New World Screwworms spend most of their time in forests and wooded areas but can seek animals in pastures and fields, if available. According to the USDA, flies are attracted to open wounds, even as small as a tick bite. A screwworm infestation begins when a female lays eggs near an open wound of a warm-blooded animal. Within a few hours, the eggs hatch into larvae (maggots) and burrow into the wound, eating the living flesh. After about seven days of feeding, the larvae drop to the ground, burrow into the soil and pupate, becoming an adult screwworm, according to the USDA. Flies emerge from the soil seven to 54 days later and then the cycle begins again. During a lifespan, female New World Screwworms can lay up to 3,000 eggs, the USDA states. Infected animals tend to show the following signs: Irritated behavior Head shaking Smell of decay Evidence of a fly strike Presence of fly maggots in wounds New World Screwworms can infest people, but this is rare, according to the Centers for Disease Control and Prevention. People are more susceptible if they travel to areas where the flies are prevalent, including South America and the Caribbean. Though rare, symptoms of a screwworm infestation in humans includes: Unexplained skin wounds or sores that don't heal Skin wounds or sores that worsen over time Painful skin wounds or sores Bleeding from open sores Feeling larvae movement within a skin wound or sore, nose, mouth or eyes Seeing maggots around or in open sores A foul-smelling odor from the site of an infestation Secondary bacterial infections can occur and may cause fever or chills. The New World Screwworm first became a significant problem in the U.S. in 1933, after shipment of infested animals from the Southwest, according to the USDA. By the 1950s, the federal government established the Sterile Insect Technique, a method that utilized radiation to sterilize male flies. These mass-produced sterile males were released into target areas and mated with females, which resulted in unfertilized eggs, according to the USDA. By the early 1960s, Southeast producers had lost between $50-100 million because of the infestations. Fortunately, the Sterile Insect Technique was a success and New World Screwworms were officially eradicated by 1966, according to USDA. Ultimately, it cost the federal government $32 million to complete. Greta Cross is a national trending reporter at USA TODAY. Story idea? Email her at gcross@ This article originally appeared on USA TODAY: New World Screwworm: What is the flesh-eating parasite?
USA Today
12-05-2025
- Health
- USA Today
What is the New World Screwworm? Flesh-eating parasite is impacting cattle imports
What is the New World Screwworm? Flesh-eating parasite is impacting cattle imports The New World Screwworm was eradicated from the U.S. in 1966. Show Caption Hide Caption U.S. suspends live animal imports due to flesh-eating parasite New World screwworms have caused the U.S. to suspend all live animal imports from Mexico indefinitely. The female flies lay eggs on open wounds of warm blooded animals and the eggs hatch in a matter of hours. Fox - 10 Phoenix The United States is halting imports of livestock from Mexico to protect U.S. livestock from a flesh-eating parasite called the New World Screwworm. The New World Screwworm, or the NWS for short, is a parasitic fly that was eradicated in the U.S. in the 1960s. The fly gets its name for how its maggots feed on an animal by burrowing, or screwing, into an open wound, creating "extension damage by tearing at the hosts' tissue with sharp mouth hooks," the Animal and Plant Health Inspection Service states. The import suspension was announced by U.S. Department of Agriculture Secretary Brooke Rollins on Sunday, May 11, following a detection of the flies in remote farms about 700 miles south of the Mexico-U.S. border. The suspension will be reevaluated on a "month-by-month basis," a USDA statement reads. Here's what to know about the New World Screwworm, including its past presence in the U.S. New World Screwworm: Parasite threat forces US to halt cattle imports from Mexico What is the New World Screwworm? The New World Screwworm is a parasitic fly, about the size of a common housefly. They have orange eyes, a metallic blue or green body and three dark stripes along their backs, according to the Animal and Plant Health Inspection Service. The fly gets its name for the behavior of its maggots, which burrow, or screw, into an animal's open wound, feeding as they go. The New World Screwworm has sharp mouth hooks, allowing them to burrow deep into an animal's flesh. New World Screwworms can infest livestock, pets, wildlife, birds and in rare cases, people. How does a New World Screwworm infestation start? New World Screwworms spend most of their time in forests and wooded areas but can seek animals in pastures and fields, if available. According to the USDA, flies are attracted to open wounds, even as small as a tick bite. A screwworm infestation begins when a female lays eggs near an open wound of a warm-blooded animal. Within a few hours, the eggs hatch into larvae (maggots) and burrow into the wound, eating the living flesh. After about seven days of feeding, the larvae drop to the ground, burrow into the soil and pupate, becoming an adult screwworm, according to the USDA. Flies emerge from the soil seven to 54 days later and then the cycle begins again. During a lifespan, female New World Screwworms can lay up to 3,000 eggs, the USDA states. Infected animals tend to show the following signs: Irritated behavior Head shaking Smell of decay Evidence of a fly strike Presence of fly maggots in wounds Is the New World Screwworm a danger to humans? New World Screwworms can infest people, but this is rare, according to the Centers for Disease Control and Prevention. People are more susceptible if they travel to areas where the flies are prevalent, including South America and the Caribbean. Though rare, symptoms of a screwworm infestation in humans includes: Unexplained skin wounds or sores that don't heal Skin wounds or sores that worsen over time Painful skin wounds or sores Bleeding from open sores Feeling larvae movement within a skin wound or sore, nose, mouth or eyes Seeing maggots around or in open sores A foul-smelling odor from the site of an infestation Secondary bacterial infections can occur and may cause fever or chills. When was the New World Screwworm eradicated from the US? The New World Screwworm first became a significant problem in the U.S. in 1933, after shipment of infested animals from the Southwest, according to the USDA. By the 1950s, the federal government established the Sterile Insect Technique, a method that utilized radiation to sterilize male flies. These mass-produced sterile males were released into target areas and mated with females, which resulted in unfertilized eggs, according to the USDA. By the early 1960s, Southeast producers had lost between $50-100 million because of the infestations. Fortunately, the Sterile Insect Technique was a success and New World Screwworms were officially eradicated by 1966, according to USDA. Ultimately, it cost the federal government $32 million to complete. Greta Cross is a national trending reporter at USA TODAY. Story idea? Email her at gcross@
