Comment by rendaw
I'm sure it's controversial, but I think general concern for the environment would increase if we killed off human-biting mosquitos. I and lots of other people avoid going outside for large parts of the year due to mosquitos. Walks, if at all, are brisk. No eating outside, no hanging out in parks, exercise at a gym, run to your car, etc. It's hard to care about the environment when you're never in it.
I guess my stance is (maybe) the benefits of getting rid of human-biting mosquitos could outweigh the negatives of the effect it'd have on ecology.