The Fall and Rise of Screwworm

goda90

I wonder if anyone ever did the math on whether trying to maintain a barrier at the Darian Gap with occasional failures was really a better financial choice than teaming up with South American countries to drive screwworms to extinction.

whalesalad

> Eventually capable of producing more than 200 million screwworm flies a week, the Mission factory was a grotesque marvel of insect-producing efficiency. Operating 24 hours a day, 365 days a year, it was, in essence, a 76,000-square-foot artificial wound. Trays full of meat, blood, and water, each one heated to the exact right temperature to stimulate screwworm growth, moved through the facility on a monorail system timed to the lifecycle of the screwworm. Imagine working at the screwworm factory.

comrade1234

Out of curiosity I looked up the cost to south American beef producers like Argentina/brazil. The extra constant animal inspections costs ~$10 per cattle up until slaughter I think. Not a huge cost but a pain nonetheless.

CodingJeebus

> Overall, the screwworm program seems like a classic case of something becoming a victim of its own success: a problem got solved so thoroughly that we forget how big of a problem it was, and we gradually undermine the conditions that made the solution possible. Chesterson's Fence strikes again. It's so easy to wax poetic about how ineffective government spending always is and should be cut to the bone that we don't stop to recognize that preventative programs like this save us from billions in economic losses.

needSomeCoffee

Thanks to the author. That was a great read imho. Loved the early parts about the guys who -- despite the ridicule and lack of resources -- achieved eradication. Again, great read.

taco_emoji

Well that's nightmare fuel D:

Planktonne

> (Some anti-screwworm efforts may have been hindered by DOGE, which cut APHIS staff, screwworm monitoring programs, and may have delayed funding for the Mexico facility, but it’s hard to be confident about this, and the administration has unsurprisingly rejected these claims.) For an article that is so detailed in other areas, this feels like a very short dismissal of a topic that--regardless of direction--deserves more focus.

srean

I have a question for folks who have background in interventions like these. Isn't there a risk that the artificially introduced reproductory pressures would select for screwworms that produce males that are resistant to radiation. My chain of reasoning is that not all the of the irradiated males would be completely sterile. If so, then the next generation would be a mix of hatchlings of not radiated parents and those parents who have not been completely sterilized in spite of radiation -- thereby increasing the proportion of radiation resistant varieties, assuming resistance is an inheritable trait. These may then find themselves at the input side of sterile male generation factories. The intervention obviously worked, but was that because steps were taken to counteract the possibility of raising radiation resistant varieties. BTW the article was a great read.

Eric_WVGG

> The Southwest Animal Health Research Foundation (SWAHRF), an organization formed by a small group of Texas livestock producers… broke the logjam by raising millions of dollars in voluntary donations from Texas ranchers for screwworm eradication. That can’t be right. The Texas Department of Agriculture published a piece titled “Dollars Don’t Kill Screwworms” just two years ago. https://texasagriculture.gov/News-Events/Article/10239/OPINI... > Listen, dollars don’t kill screwworms. Sterile flies do. Detection systems do. We already have the tools to manage this issue because we’ve been doing it successfully for decades. See? We don't need big government programs to get this under control, we just need farmers to… I dunno… raise and breed their own own sterile flies, or buy them from Walmart.

dang

Recent and related: Oh good, screwworms are back (2025) - https://news.ycombinator.com/item?id=48475898 - June 2026 (79 comments) First U.S. screwworm case confirmed in South Texas - https://news.ycombinator.com/item?id=48397036 - June 2026 (34 comments)

mschuster91

> And when it was clear that screwworms had breached the barrier, responses were sometimes delayed by political disputes — Mexico apparently initially made it very difficult for USDA screwworm flights to operate until the US Agricultural Secretary called to force the issue. DOGE aside, as the article and commenters already mentioned that - if that giant buffoon Trump wouldn't have gone and screwed up relations with virtually every country south of the US sans Argentinia and El Salvador, including invading Venezuela to oust their president, maaaaybe other countries wouldn't find the risk of screwworm more acceptable than risking American government flights over their countries. The damage the two Trump administrations caused will take decades to repair. And frankly if I were a country south of the US - I'd invest in my own resources to combat screwworms. There simply is no guarantee that, even if Trump fails and someone sane is elected in two years, they won't elect someone just as braindead in six years.

Metacelsus

Time to bring out the gene drives!

yread

It sounds like the original research done 30s-50s would not be possible today. No one is getting an ethics approval for that. And "let me just get some cobalt-60" is probably also not happening

SoftTalker

It's a bit odd that the screwworm exists. Normally a parasite that kills its host is at an evolutionary disadvantage. I wonder if the human practice of keeping large groups of livestock together in close proximity creates an unnatural "target rich environment" for the flies that they don't otherwise experience, making them much more of a problem.

AndrewKemendo

Wow the thing that stood out to me was the number of Darien Gap crossing not being zero. I was under the impression that was the most dangerous part of the planet for every possible reason. The fact that it’s half a million a year is crazy! Something must have changed in infrastructure for that to even be possible right?

thelastgallon

Can a similar thing be done for mosquitoes by dropping sterile males?