There is no finishing the job. Screwworm flies have tons of reservoirs in the jungles of Central America that aren’t practical to eliminate for logistical and ecological reasons. We can only control the population in agriculturally important areas by constantly releasing the sterile male flies every year. Whenever we stop the releases, the flies bounce back in a few years.

The durable reservoirs are in South America, not Central America. We actually eradicated it (at least essentially) all the way down to the Darien Gap.

See I guess I find broadside “impractical” dissatisfying.

Could a few cargo ships be converted into floating fly farm aircraft carriers on either coast, maybe another in the amazon, and then just use a hundred reaper drone type things to do a creeping barrage? This must be within the budget of even a modest nation state.