In many parts of the country or world spraying is used to control mosquitos. Spraying not only kills the fast majority of mosquitos in an area but likely kills other bugs in the area as well. If wiping out the mosquitos eliminated an important food source for other species, we would be seeing a significant decline of other species in areas of heavy spraying. While I'm not arguing for eliminating mosquitos without seriously looking at it, spraying will continue as will the environmental consequences of spraying until it happens.
Additionally, our politicians always are saying "if the life of one child can be saved...." give up your freedoms. People seem to be pretty ready to live under onerous government rule to save that one (or twelve) lives per year saved. Well, here we have a situation where we can measure what the worth of a human life truly is worth.