Why screwworm is coming for your beef

[00:00] If I were to tell you that the US government breeds sterile male flies to mate with female flies in Central America, you might ask, why? Why is a perfectly reasonable response to that?

[00:16] That's ridiculous, that's a scam on the American taxpayer, that is not a reasonable response, but why absolutely is? Curiosity, curiosity, my friends, curiosity over reflexive anger and

[00:33] suspicion, curiosity over anger. If something doesn't make any sense to you, don't get mad, get curious, and then get mad, if warranted. Anyway, as many people are learning the hard way right now,

[00:50] the whole sterile fly breeding thing is actually really important for the US beef industry, especially. Why? Well, let me see if I can put this in the most dramatic way possible while

[01:03] still being essentially accurate. That was my job. Back when I wrote copy for traditional broadcast news organizations, most dramatic way possible while still being true. A worm that feasts on

[01:18] living flesh is coming for your livestock, for your pets, and maybe even for you. In recent weeks, US agriculture officials have reported the very first confirmed

[01:33] screw worm infestations to reach mainland United States since the 1960s. The way that we eradicated them back then was by breeding sterile male flies and releasing them,

[01:49] eventually mostly in Panama. That effort, as much as any other, is what allowed the southwestern cattle industry to thrive in the US, which reminds me to thank thrive market sponsor

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[03:20] get $20 off your first three orders, and a free gift. Thank you Thrive Market. Anyway, we drove screw worm fully out of the United States 60 years ago by breeding sterile flies. It worked,

[03:35] but now, as of this summer, the screw worms are back, and it's probably going to be a problem. Not a beef industry ending problem, but a problem that will probably raise prices.

[03:51] And if you're looking for blame, there is plenty to go around. Though the distribution may not be strictly speaking equal, I actually think that the subject of blame is still an open question here,

[04:03] and we will get back to that. The new world screw worm is technically not a worm. It is the larval stage of a fly. See hominivorex, which means that it is technically a maggot rather than a worm,

[04:19] and maggots eat flesh. Flies are attracted to the smell of dead or dying animals. The females lay their eggs, and when they hatch, the maggots fuel their rapid growth with readily

[04:34] available animal protein. This is not unusual. People across cultures have four millennia use maggots to clean wounds. They eat in a chronic tissue, the dead part of the wound that you need to get rid

[04:49] of. maggots do not eat living tissue. Unless you're talking about sea hominivorex. The larvae of the new world screw worm do eat living flesh, which is reason number 10,000 and one

[05:07] while you probably shouldn't administer surgical maggots to your own wounds, because you might have the kind that eat live tissue, not the dead tissue, and that would be very bad. The fact that

[05:19] sea hominivorex eats live tissue presents a problem not only to ranchers, but to forensic scientists who use the presence of maggots on a body to determine the rough time of death.

[05:33] That estimate will be wrong by several days if the maggots happen to be new world screw worms, because they can start eating long before rot has set in. So if you need to dump a body,

[05:46] dump it with some new world screw worms, and that might throw them off your trail for just a little bit. JK, anyway, the screw worm generally enters through a wound. That's how sheep and cattle and such usually

[05:59] become fly struck as they say. The animal gets a little scrape. The mama flies smell it and they lay their eggs. The larvae hatch and then they burrow deep into the animal in the manner of a screw,

[06:16] looking for healthy tissues to eat, and that damage leads to bacterial infection that eventually kills the animal. This used to cause significant losses for the livestock industry in the parts of

[06:28] the Americas that are very hot and humid, which is what the screw worm likes. Florida, for example, the Caribbean. South America, Central America, Mexico, and up into Texas, where in 1909, a guy named

[06:44] Edward Nippling was born. He grew up on his dad's ranch. He saw how awful the screw worm was. He trained as an entomologist, went to work for the U.S. Department of Agriculture, where he met

[06:57] Raymond Bushland and the two of them cooked up an idea. They noticed that the new world screw worm fly has a curious reproductive vulnerability. The female has a special sperm storing organ.

[07:14] The male fills it up and then she has all the sperm she will ever need to fertilize eggs for what remains of her weeks-long lifespan. If another male tries to mate with her after that, his contribution

[07:30] will have nowhere to go, so the females effectively can only mate once. What these two young scientists in the 1930s figured was, well, what if you flood the zone with sterile male flies?

[07:48] You breed the flies, you irradiate them to kill their sperm, then you release a ton of them into the target area. They hopefully outcompete the fertile males, they shoot their blanks, and then all of the

[08:03] eggs those females lay will never, ever hatch. That work was interrupted by World War II. Reason number 10,001, why war is bad? We could have eradicated screw worm decades earlier, but

[08:21] they got back to it in the 50s, they did a pilot program in Florida, and by the late 60s, they had pushed the screw worm entirely out of the southern United States. By the 90s, they had pushed it out of Mexico, and by the early 2000s, they had reached the Darian gap,

[08:39] that little narrow isthmus in Panama that just barely bridges North and South America. The US and the Panamanian government partnered on a sterile fly factory down there that still operates,

[08:53] and for a while, we were able to contain the screw worm pretty cheaply, because you don't need that many sterile flies to cover an incredibly narrow land area. We had cut them off effectively.

[09:08] But then they started creeping back up North. There was a little outbreak in the Florida Keys in 2016. It affected like half a dozen domestic dogs and such, but mainly it got the key deer,

[09:25] which are these adorable like many deer that roam wild on the Keys, which are islands off the southern tip of Florida if you didn't already know that. Nobody knows how the flies got to the Keys.

[09:37] They could have blown there on strong winds from Caribbean islands, maybe an infected pet or a livestock animal was introduced by someone, but the Keys are a small, contained area. The government

[09:50] introduced some sterile flies and that took care of the problem in a few months is going to be a lot harder down in Texas. The screw worm escaped containment in Panama and caused an outbreak in

[10:04] Mexico in 2024. Why? How? Nobody knows. But the relevant scientists who have been speaking on this topic publicly say that it is probably some combination of the rapidly warming climate,

[10:22] making the environment much more hospitable for screw worms up here, and perhaps human migration. People fleeing violence and drought in Central America looking for safety further north,

[10:37] a few bringing livestock with them. Humans can also be infected any any warm-blooded animal can. Between climate change and migration, there's something for every U.S. political faction to blame

[10:52] this on, and that's what really matters, right? I will point out that northward migration is in part driven by climate change, so same difference. Also, there's a third possibility that it's spread via

[11:08] cattle smuggling. There is a well-documented problem of ranchers grazing cattle illegally in the relatively unstable countries of Central America, where you can get away with grazing on government land,

[11:21] or nature preserve, that kind of thing, and then you smuggle the cattle into Mexico where there's a big market for it. When screw worm popped up into Mexico again, officially confirmed in late 2024,

[11:34] everybody knew it was only a matter of time until it got back to the U.S. It could spread up here via wild animals. The key deer outbreak that proved as much. There is also cattle smuggling that happens

[11:49] across the U.S. Mexico border. We immediately shut down live cattle imports from Mexico when all of this started back up, but that probably creates an even greater incentive for smuggling.

[12:01] Everybody knew that screw worm was coming back to the U.S., but this all came to a head right at the transition between the Biden and the second Trump administration. Upon retaking office, Trump tasked his

[12:15] funder, Elon Musk, with rooting out ostensibly wasteful government spending, the so-called department of government efficiency or doge. Here is what we know and what we don't know about doge

[12:30] and screw worms. Doge did shut down USAID, the foreign aid agency, and in doing so, they cancelled U.S. funding for United Nations Food Security programs. Among the programs defunded were

[12:46] bird flu and screw worm monitoring and containment efforts, and shortly after U.S. funding was cut, those programs were shut down. That is all according to an anonymous source cited by the agricultural

[13:02] trade publication AgriPulse. When people say that doge cut money to stop the screw worms, they are citing this singular report with an unnamed source. That is, in the opinion of this

[13:20] former journalism teacher, Thinsourcing. I'm not saying it's wrong. It definitely seems like something that would have happened. We know that doge was just cutting things that they didn't recognize

[13:35] or understand, and fly monitoring in Panama for sure sounds like something that they just would have cut, but we have to be careful here. We ought not round probable up to certain. Unlikely outcomes

[13:50] happen all the time. What we know for sure is that US response to screw worm is centered on the US Department of Agriculture, and doge and the Trump administration fired or otherwise pushed out about

[14:07] 20,000 USDA employees right as this screw worm situation was really starting to heat up. That is about 15% of the USDA workforce, and all of their institutional knowledge just gone almost overnight.

[14:24] How that effective the screw worm problem is something I doubt we will know for years, once some tell all books have been written. Regardless, the agricultural lobby obviously succeeded pretty

[14:39] quickly in ringing alarm bells with the Trump administration because starting in the spring of 2025, we started partnering with Mexico on building a bunch of new sterile fly production facilities, and we started building a big new one in Texas that won't be operational for another year.

[14:58] Bad news. Considering that just this month, June of 2026, the USDA confirmed five screw worm cases. The first mainland US domestically transmitted cases since 1966. Three heads of cattle and a goat in

[15:18] Texas and a dog in New Mexico, it begins. Just because an animal is infected doesn't mean it's a loss. You can easily treat screw worm with cheap anti-parasitic drugs if you catch it reasonably early,

[15:33] but that requires catching it reasonably early. Regarding humans, none of the experts are raising any alarm about this from like a food safety perspective.

[15:46] It could be an occupational safety issue. A person working on a ranch, the flies can lay their eggs on a scrape or a cut, but also any other body opening. That's fun.

[15:59] Look, this is a problem that we know how to fix and we've fixed it before. We'll probably fix it again. The experts say we do not have the sterile fly capacity to re-eradicate screw worm just yet,

[16:14] but we should have it soon, ish. In the meantime, ranchers will be spending lots of extra time and resources in monitoring their herds and treating any infections. This will cost money.

[16:29] Beef is already quite expensive right now. For a few reasons, but the biggest one just being drought. The US cattle population is at a 75 year low right now, chiefly due to drought.

[16:43] The industry analysts that I've seen commenting on this issue say that screw worm will probably just keep the prices high, roughly where they are, for quite a while longer, unless the problem gets really

[16:55] out of hand. That's not why I am talking about this. I think that we could all stand to eat a lot less beef for a lot of reasons, so I don't particularly mind a little upward price pressure.

[17:11] Easy for me to say. Sit in here with my YouTube money. Your consumer activity is your own business. The reason I just talked about screw worm for however many minutes that was is that this is a situation that reminds us yet again how interconnected our

[17:29] whole world is. A rich country spending money to fight disease in a poor country isn't just about doing a good deed. It is also self-interest. Sometimes all it takes is a stiff breeze to make

[17:45] somebody else's problem your problem. Which is another reason why I am grateful to have a large professional civil service working for me, and I am proud to pay for it with the sickening amount

[18:01] that I pay in Texas every year. A century ago the government took a ranch kid in Texas, the government trained him at public research universities, hired him to be a bug scientist,

[18:15] and that guy came up with a fix for screw worm. When people talk derisively about the deep state, they are talking about some real things that are really bad. I will grant you, but they are also

[18:28] talking about Edward Nippling. Edward Nippling was also the deep state, and it's a good thing he was because his research is what is going to save us from the flesh eating worms. Thank you for your service,