Is it a good idea to leave alive mosquitos that don't bite humans? How long would it take them to mutate and fill the "human bloodsucking" niche that is suddenly vacant?

Perhaps a more comprehensive program of disease vector eradication is in order. Any organism that acts as a flying hypodermic needle poses the risk of moving pathogens around between species. For that matter, there are a lot of parasites in the world that parasitise mammals. If they were all to be eradicated, predators could take up the slack, but predators such as foxes, wolves or lions are trivially easy for us to control in comparison.

Natural ecosystems are de facto bioterrorist labs that occasionally output horrors like AIDS and ebola and zika. Maybe human beings need to start a serious and far-reaching effort to shut them down.