> We already have medicines that treat the problem

We do have treatments of screwworm infestations, but it involves physically removing the larva and usually removing tissue as well as systemic treatments like antiparasitics. It's labor intensive and not cheap.

It also doesn't actually fix the _overall_ problem because screwworms will happily lay eggs in wild mammals too and so you will constantly be treating your livestock.

> We've had it solved for a long time

Yes, we solved it with mass releases of sterile flies over decades.

Yeah we did have it solved for a long time. We had no screwworms at all in the country. That was a great solution that lasted decades. Why would having to do all the work of applying medication, paying for the medication, animals that you catch late dying of infection and paying for those animals, people occasionally getting screwworms, pets dying to screwworms, etc etc etc be better or cheaper?

Also they don't genetically modify flies they still just irradiate the larva.

> We didn't need to genetically modify flies [...]

"Involve transgenics" is broad enough cover the intern doing literature reviews on related subjects. The discovery process on an unfamiliar domain is a jargon/term of art minefield, and the phrases that fly past me turn in to shibboleths.

We didn't need to genetically modify them, we just sterilized them with x rays and the released masses of sterilized flies into the population. We had that tech in the 50s and wiped them out in the 60s. The best treatment we had was eliminating them from the United States and that's no longer reality.

Is this what ivermectin actually treats? Everything comes full-circle.