Anthropogenic emissions of greenhouse gases are enhancing the natural greenhouse effect. It is almost universally accepted that this will lead to a warming of the earth's surface. It is also accepted that this warming will lead to a spread of the insects that transmit several infections, currently restricted to the tropics, such as malaria, leishmaniasis, yellow fever, and dengue fever, among others. We calculated the expected increase in the density of female adult forms of anopheline mosquitoes by assuming temperature-dependent functions on