Natural enemy systems that persist in the environmental increase their effectiveness through field reproduction, and may coevolve with their hosts to minimize the development of resistance to pesticides. Some biotic insecticides are commercially available for short-term direct mosquito control, which may be vital to exploit for malaria control in countries where technology is not advanced. A few examples of long-term persistent biological controls exist. A comprehensive view of biological control differentiate geographic areas, habitat characteristics and levels of human tolerance, and distinguish purely mosquito annoyance problems from life-and-death disease vector impacts on humans in technologically underdeveloped areas. The future of biological mosquito control is dependent on additional research, especially the discovery of capable new species and strains of organisms. With resistance to insecticides a compounding problem, biological control in concert with practical breeding site modification, may be the only range tactic to reduce mosquito densities over a broad expanse of the world.