That still remains to be seen, right? Wasn't the first release of gmo mosquitos only recently in Florida?
No, there were several earlier trials. I think there were issues in scaling up the mosquito modification process.
There is a very scalable process. You breed mosquitoes, about half of which have the gene you're after (so the population isn't infertile). You have machines that can sort them very quickly, and you only release to the wild the infertile male ones. I made a sorting machine that can sort 10 larvae per second - it's all just computer vision looking at their microscopic balls!
Reach out to Tom Scott (I'm serious, he is very responsive to e-mails) and he'll probably make a video about this, especially if you are in the UK like your name suggests. I know I would love to see it.
Sick, thanks for the process details. Are there plans for larger releases? if not, do you know what is preventing that from moving forward?