Deadly Screwworm Parasite's Comeback Threatens Texas Cattle, US Beef Supply
189 comments
·May 3, 2025throwup238
This is why a competent and well staffed bureaucracy is so important. Screwworm is really easy to eliminate by flooding their population with males sterilized by radiation (females only mate once in their lifetime so their population falls off fast). There are factories in Latin America already set up to do so at large scale, all it would take is a contract with the USDA to guarantee enough supply for the states.
Edit: Hah, I get to eat my words. Turns out USDA and APHIS have been trying to fly planes over Mexico to release the sterile flies, but the Mexican government has been restricting the flight days and denying landing permission, which has hampered the program. Looks like the Mexican bureaucracy is the one failing here, and USDA/APHIS might be running pre-emptive releases in the US (but I can't find a source on that). They just agreed to lift those restrictions and cooperate more at the end of April.
jimnotgym
Good job the US is on such good terms with Latin America at the moment
stevenwoo
It was partially the new tariffs that put a stop to the program and the April 30 agreement puts an end to tariffs on equipment associated with screwworm treatment program.
drivingmenuts
That competent and well-staffed bureaucracy is important also because they patiently work through these problems with their counterparts on the other side of the the Rio Grande.
Except they got fired, so now there's no one to do that work. We got what we wanted. God help us all 'cause no one else is.
dmckeon
And now those positions are listed as open. Disruption, but to what end. Sigh. https://text.npr.org/nx-s1-5384961
andsoitis
> There are factories in Latin America already set up to do so at large scale, all it would take is a contract with the USDA to guarantee enough supply for the states.
According to the article the cases are in Mexico, so I don’t know that “Latin American origin” is a silver bullet.
bastawhiz
Why wouldn't the USDA pay to eliminate pests in another country if it meant preventing those pests from reaching US farmers?
dessimus
> Why wouldn't the USDA pay...
Maybe because there is an executive body hell-bent on the slashing expenditures regardless of any perceived benefit?
creato
They did exactly that for decades.
giardini
Better if all parties who benefit also pay.
ikiris
Doge probably saw it as anti male propoganda. THEYRE STERALIZIN OUR FLIES
slicktux
Mexico is just a small portion of Latin America; A few places I can think of is Uruguay, Argentina and Brazil which have huge stockyards…
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pfdietz
> their population falls off fast
Superexponentially fast.
tomohawk
[dead]
krunck
> This is why a competent and well staffed bureaucracy is so important.
Try: "This is why a competent and well staffed science institute is so important."
Bureaucracy not required.
matthewdgreen
Who exactly do you think staffs this part of a science institute? Bureaucracy is just another word for the kind of well-staffed administrative system that can handle these tasks.
fallingknife
I think a lot of the objections here aren't really bureaucracy in terms of government employees doing things. A lot of what people mean when they complain about "government bureaucracy" is really that it often seems to be 20 people taking 6 months to do something that should take 5 people 6 weeks. So discussions on this tend to get confusing.
8note
the administrative parts - managers and approvers, aren't doing the science or the application thereof.
a couple university students in a van going around releasing flies every 10 miles is not a bureaucracy, nor a stand in for a bureaucracy
danso
How is a bureaucracy not required when the solution involves coordinated multinational logistics to produce and distribute hundreds of millions of flies?
johnisgood
Yeah because bureaucracy (in its original term) is efficient at that. /s
Wait a couple of years, and then maybe.
kergonath
The science is done. We know how to deal with this insect, the American government successfully eradicated it from North America ~25 years ago. Now it’s only logistics and diplomacy.
accrual
This topic always leads me back to reading about the Darién Gap [0]. When eradication was working successfully, they had managed to push the screwworm population all the way back to the Gap and keep it out of major population/agriculture areas. There were (or are) yearly efforts to perform the sterile insect technique [1]. Expensive to perform, but worth it for all the damage they'd otherwise cause if left unchecked.
beached_whale
Not expensive at all. 10s of millions of dollars a year is my understanding.
bglazer
$200 million in total, approximately the cost of two (2) F35B fighter jets
https://cr.usembassy.gov/sections-offices/aphis/screwworm-pr...
janice1999
Arstechnica reports it "is estimated to have saved US farmers $900 million every year." Not sure where they source the number from.
https://arstechnica.com/health/2025/05/screwworms-are-coming...
beached_whale
Ah thanks. I thought it was lower, but in the scheme of things it's still cheap and it prevents people from getting it too.
chasil
I had confused botflies for screw worms, but they are different.
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snowwrestler
More on the screwworm barrier and how it was established. This is one of my favorite “magazine style” feature stories.
https://www.theatlantic.com/science/archive/2020/05/flesh-ea...
jauntywundrkind
Salon had a lovely article last week, on how deteriorating relationships between US and Mexico is threatening the effective work the US had been doing of creating and spreading sterile male flies that have successfully stopped the Screwworm invasion. https://www.salon.com/2025/04/28/we-once-rid-the-us-of-this-...
canucker2016
Ars has an article on screwworms - 1 guess as to the writer.
see https://arstechnica.com/health/2025/05/screwworms-are-coming...
The last word of the article has a link to a video with very unsettling imagery involving screwworms.
giardini
>Outside a bar in southern Arizona in 1890, a stagecoach driver stumbled into the night and fell asleep in the open air, unknowingly becoming host to hundreds of screwworms while passed out drunk. The parasitic insects made their way through his nose, into his throat, and eventually killed him — a grim but once relatively common occurrence.<
From
"Screwworm eradication lessons from a longtime veterinarian"
https://www.agdaily.com/livestock/screwworm-eradication-less...
An excellent article on the realities of screwworm in USA. It also speaks of topical treatments! Unfortunately though and to our great loss no doubt, it does not go into detail about "the scrotal area post castration" of unsnap_biceps fascination on these posts nor "lambs ...licking the topically applied ivermectin" so titillating to 8note. (FWIW ivermectin pour-ons contain ethanol.)
neuroelectron
Is ivermectin not an option? My fat pet rat got mites and was miserable, itchy and too painful to scratch. One grain of rice dose from the infamous horse tube cleared him right up.
unsnap_biceps
https://pubmed.ncbi.nlm.nih.gov/3840994/ Seems to show that it does, but I guess the logistics of keeping a herd of cattle covered by giving shots every two weeks may be difficult. And there still is damage to the animal
MillironX
https://pubmed.ncbi.nlm.nih.gov/9403981/
The article you referred to (and I've seen linked elsewhere in this thread) is about "regular" screwworm (Chrysomya bezziana). The recent outbreak is of New World Screwworm (Cochliomyia hominivorax). The article I've linked suggests that it is much harder to kill than regular screwworm (29% of calves developed myiasis even when treated with ivermectin).
giardini
Googling "Cochliomyia hominivorax and ivermectin" yields
"Ivermectin can be an effective treatment for myiasis, a condition caused by the larvae of certain dipterous flies, including Cochliomyia hominivorax (the New World screwworm). Studies have shown that ivermectin, when administered orally or topically, can help eliminate the larvae and reduce the severity of the infestation, especially in cases of orbital or oral myiasis. "
giardini
Ivermectin liquid "pour-on" is poured along the backbone of cattle (just as you do in cats and dogs with flea medications).
unsnap_biceps
The study I linked to showing the effectiveness of Ivermectin was only done subcutaneously. I did not find a study on the effectiveness of non-subcutaneous Ivermectin treatments on screw worms.
Given one of the areas they focused on the study is the scrotal area post castration, I don't expect that a pour on would cover that area well enough to be an effective treatment. Happy to read other studies if you have them showing otherwise.
ceejayoz
There’s also resistance to worry about if used widely.
kergonath
You still need to remove them, otherwise you have decomposing maggots in an infected would, which is a great way of killing whatever you were trying to save.
drumhead
This is going to be a test of the "new improved" post Doge USDA. We'll see how well it copes with a real agricultural crisis with reduced staffing and funds.
toofy
indeed. it will also not be limited to one agriculture crisis. the number of things these departments do that we don’t realize is crazy. putting out fire after fire.
since these departments generally don’t brag about non-sexy things like … screwworms, a certain type of person with tunnel vision, who imagines themselves to be smarter at everything than everyone else that has ever lived, they will imagine they failed not because of their own dipshittery but because of an imaginary ghost foe.
this is perhaps one of the greatest failures of that generation, so many of them seem to have a complete inability to see that other people may be intelligent at something. their tunnel vision is crazy af to see.
it’s gonna be hilarious to watch them cry about the messes they caused. they’ll try to blame everyone else for the mess they created.
danso
Tangential aside but what does this mean:
> live demonstrations on how to handle cattle to reduce stress.(Every cow pie released by a stressed-out cow before it gets weighed by meat processers amounts to $6 in lost profit.)
unsnap_biceps
Ranchers get paid a flat per pound price for whole animals. When they take a shit, their total weight goes down and thus the ranchers lose the flat per pound price for that pile of shit, which evidently is about $6.
reverendsteveii
It's a great day to be heavily punishing imports!
heresie-dabord
Heavily punishing your own citizens for buying imported goods in a highly-integrated global economy.
unfitted2545
good day to be a vegan.
vips7L
It’s always a good day to not participate in the cruelty and evil that is animal farming.
timschmidt
There's a big difference between https://en.wikipedia.org/wiki/Concentrated_animal_feeding_op... and traditional family farms. In a traditional family farm, animals can live happy and relatively full lives while offsetting a tremendous amount of petroleum products in the form of fuel, insecticide, herbicide, fertilizer, equipment, etc.
aziaziazi
> traditional family farms.
> relatively full lives
Thanks to point out the difference between industrial and family farm. However I'm not sure what farms in particular you have in mind but anything commercial has non incentive to let the animal live a "relatively full life": the meat of a relatively old animal taste far from what people are used to eat and is (way) more expensive to produce. Some producers add a few weeks to the legal minimum to let them grow a bit more but nothing near their natural expectancy. Lets take chickens for exemple, here in EU:
- standard are harvest 35 days (32 if for export)
- certified (floor, outdoor) at 56 days
- highest quality (Bio and local certifications): 81 day
- egg poultry final harvest: around 1 year and half when egg production slow down
- natural life expectancy of a chicken: 8-10 years.
> can live happy
"happier" would be more accurate IMHO but as some people point our frequently: we can't know for sure how another animal feels so it's only guess. What we can do is remove the farm fences and do not force them onto the slaughter house. They'll choose themselves to go to what makes them happy.
chneu
No there isn't. This is just stuff y'all tell yourselves to make ya feel better about your cruelty and over consumption.
vips7L
Whatever lets you sleep at night my friend.
herpdyderp
These infect humans too, vegan or not.
scandox
I first learned about these delightful creatures after reading The Screwfly Solution by Alice Sheldon:
andsoitis
” Now, after being eradicated from the US since the early 1980s and largely forgotten, top veterinarians expect the screwworm could be back as soon as the summer. More than 950 cases have been reported in Mexico so far this year, including one within miles of a livestock checkpoint in Chiapas. A resurgence in the US would have devastating consequences for farm animals and wildlife”
e40
I was surprised to learn recently that we import a LOT of cattle. It's the reason many other countries will not take US beef, because the provenance of our beef isn't as precise as it needs to be, for those foreign consumer laws.
chneu
We also treat our cows with antibiotics that a lot of countries ban. A lot of our meat is also treated with chemicals that other countries ban.
It's why Europe won't import a lot of US beef.
ujkhsjkdhf234
This is true of a lot of our food. Trump, now and in 2016, has been trying to force the UK to buy US chicken and the Brits are NOT having it because US food standards are below that of the UK.
gruez
[flagged]
https://archive.is/ul6JR