"And what are the effluents that are to be abandoned by tolerating? There is the case where a monk, reflecting appropriately, endures. He tolerates cold, heat, hunger, & thirst; the touch of flies, mosquitoes, wind, sun, & reptiles; ill-spoken, unwelcome words; & bodily feelings that, when they arise, are painful, racking, sharp, piercing, disagreeable, displeasing, & menacing to life. The effluents, vexation, or fever that would arise if he were not to tolerate these things do not arise for him when he tolerates them. These are called the effluents that are to be abandoned by tolerating."
http://www.accesstoinsight.org/lib/auth ... part2.html
There is the case where a monk
And here you have an important distinction. Much more is expected from the Buddha for his monks than that which he expects of lay people. When I was younger and very keen and passionate about ordaining, I was staying in Bodhinyanarama in Wellington and I was very passionate about austerities and such like, I would deny myself all kinds of comforts that were on hand, for a time I was living more austere than the monks. I wore myself out in the end through all my austerities and had to readjust to a more comfortable middle ground in order to continue making progress.
So I'm always careful to point out whenever anyone quotes the passage you have above, that such things should be developed over time and only really for those who are intent on fast tracking their way to Nibbana. As for enduring mosquito bites, I did that very thing in Sri Lanka in Meetirigala in the middle of the forest, my legs ended up looking like a pizza, some of the monks would stop and go "Ohhh! Look at those legs!" and they would come up and examine my legs and it was fascinating to them. Apparently the mosquitos don't like the Singhalese blood as much, apparently it has something to do with the smell that us humans put out, mosquitos can smell us, and some smells are more attractive than others.
One of the monks knew of this also and suggested that the mosquitos there preferred Suddhas (white person) blood as it must have had different characteristics to the native Singhalese in the area. It was actually kind of dangerous to go without deet now that I think about it, because there were mosquitos present in the area that carried Dengue fever, Malaria & Jap Encephalitis - It was quite uncommon, but it happened from time to time and a few people in the area got Dengue each year and occasionally someone came down with Malaria. After some time I went back to wearing mosquito repellent and decided this was one thing that didn't need to be mindfully endured. Frankly, it was hard to meditate when you can hear the mosquitos buzzing around, landing on you - In your ear, on your nose, just about everywhere, and then the incessant itching that follows.
Now regarding genetically modifying mosquitos so they can't breed? I see absolutely no problem with this. Mosquitos are the cause of much suffering in this world,, and genetically modifying them is not killing, therefore it's a much better solution than spraying large swathes of land with chemicals to kill them (and inadvertent kill other insects or beings or at least make them sick). Types of mosquitos who are a vector for any disease at all should be made infertile, it's the perfect solution.