By Daily Mail (U.S.) | Created at 2025-01-05 01:31:24 | Updated at 2025-01-06 21:55:35
1 day ago
A fly that lays flesh-eating larvae could threaten humans and wildlife in Texas after it has been detected in Mexico.
The Texas Department of Parks and Wildlife issued an urgent warning to its Southern residents to keep an eye out for the New World Screwworm, whose Latin name, hominivorax, means 'man-eater.'
The warning comes after a cow was found with the larvae at an inspection checkpoint in Chiapas, near the Mexico-Guatemala border, on November 22.
'As a protective measure, animal health officials ask those along the southern Texas border to monitor wildlife, livestock and pets for clinical signs of [the insect] and immediately report potential cases,' the TPWD said in a statement.
The screwworm has been 'progressively' migrating northward, according to the agency, and it primarily infects livestock.
It can, however, affect humans and wildlife, including deer and birds, TPWD said.
The parasite hasn't been seen in the US since 1966 after extensive federal and state sterilization process managed to eradicate the fly from the States.
Experts are worried it could have a devastating effect on the US economy if it were to reach the US.
The Texas Department of Parks and Wildlife has issued an urgent warning to its Southern residents to keep an eye out for the flesh-eating New World Screwworm, whose Latin name, hominivorax, means 'man-eater'
The warning comes after a cow was found with the larvae at an inspection checkpoint in Chiapas, near the Mexico-Guatemala border, on November 22. The parasite hasn't been seen in the US since 1966 (pictured: El Paso, Texas)
A map showing where the screwworm currently is and how deep into the United States it is expected to penetrate by 2055
'It can have a huge impact, certainly an economic impact, because it decreases the health and wellness of our livestock,' Texas Tech School of Veterinary Medicine Associate Professor Jennifer Koziol told Drovers.
'We’re thinking about loss of animal use, and certainly thinking about our wildlife populations that could be decimated by this disease.'
The screwworm begins its reign of terror when the female fly lays her eggs into an open wound or orifices.
The female flies are drawn to the open wounds and orifices by the odors they emit. They can be as small as a tick bite, a nasal or eye opening, a navel of a newborn or genitalia, the TPWD said.
These eggs then hatch into dangerous larvae that burrow into the wound like screws, according to the agency.
Female flies can lay up to 200 to 300 eggs at once and up to 3,000 in her lifetime, according to KHOU 11. Infestations can also be visible on the skin.
Infections can be deadly and are often serious. The New York Times reported in 1977 that one infection could 'kill a fully grown steer in 10 days.'
The government organization recommends covering all open wounds, especially if traveling in affected areas, such as Central or South America. It also recommended wearing insect repellant while hunting, hiking or bird watching.
Experts are worried it could have a devastating effect on the US economy if it were to reach the US. 'It can have a huge impact, certainly an economic impact, because it decreases the health and wellness of our livestock,' Associate Professor Jennifer Koziol (pictured) said
The screwworm begins its reign of terror with a female fly laying eggs into an open wound or orifices. These eggs then hatch into dangerous larvae that burrow into wounds like screws
Signs of a screwworm infection
These are the symptoms of a screwworm infection:
- Irritated or depressed behavior
- Loss of appetite
- Head shaking
- Smell of decaying flesh
- Presence of fly larvae (maggots) in wounds
- Isolation from other animals or people
- Wounds that do not heal
- Wounds like worsen over time
- Seeing maggots in the wound
Source: TPWD and CDC
The Sterilization Project
When screwworms became a major problem in the US, it cost the US $200 million - roughly $1.8 billion today - in livestock, according to KHOU 11.
In the 1930s, the US Department of Agriculture hired a team of scientists, including entomologist Edward F. Knipling, to study the fly, according to NPR.
Knipling had the idea to develop birth control for male flies, and despite his detractors who thought there was no way to sterilize enough of them, his plan worked.
He hypothesized that sterilized flies released into the wild would cause the fly population to diminish and eventually eradicate from the States.
For more than two decades, he and Raymond Bushland worked to castrate flies by growing millions in a lab by using warmed up ground beef, according to NPR.
Using gamma rays, they were able to make the flies infertile.
By 1958, the two scientists convinced the government to begin airdropping 50 million flies in Florida each week.
As more were dropped, the screwworm began to disappear in the state and by 1959, the fly was gone from the Southeast.
'From there, the snowball got rolling,' Knipling said.
Flies began being dropped over Texas, as well as the Southwest and Mexico and Central America.
In the 1930s, the US Department of Agriculture hired a team of scientists, including entomologist Edward F. Knipling, to study the fly. Knipling had the idea to develop birth control for male flies by releasing sterilized flies into the wild. It worked
For more than two decades, he and Raymond Bushland worked to castrate flies by growing millions in a lab by using warmed up ground beef. Using gamma rays, they were able to make the flies infertile. By 1966, the last of the flies were eradicated from the US
By 1997, the screwworm was wiped out from Panama to Texas.
The Agriculture Department still drops flies over Panama to prevent the insects from traveling from South America back to the US.
'It creates a buffer zone,' the scientist said.
The UN called Knipling and Bushland's work one of the 'greatest achievements in animal health' in the 20th Century.
In September 2016, the scientists were honored with the Golden Goose Award, which honors federally funded research that was 'seemingly obscure' that eventually lead to major breakthrough, according to NPR.
The research went beyond the screwworm and was used to keep the Mediterranean fruit fly out of North America and helped get ride of the melon fly from Okinawa in Japan.
