Genetics may provide humankind its most comprehensive answers in controlling the age-old scourges of malaria, dengue fever and West Nile virus by eliminating the ability of vector mosquitos to host the diseases. But the new genetic solutions that involve introducing engineered malaria-resistant mosquitos or mosquitos replete with engineered resistant gut bacteria raise questions of their own. How large of a population with the genetic trait will be needed to be viable? Will the population survive, persist and mate with wild mosquitos? Is it possible to completely overtake the susceptible wild population with resistant mosquitos? Among the large number of biological factors involved in such a process, what are the most sensitive and important ones to make the genetic solutions work? As far as the release of genetically altered mosquitos into the field is concerned, what are the better strategies for that biologically as well as economically?