Mosquito-borne diseases (malaria, !lariasis, dengue, chikungunya, etc.) represent dramatic health problems, mainly in developing countries where these diseases are endemic. Different integrated approaches have been aimed at both vector control and disease control, the most popular represented by the application of DDT and other insecticides. Insecticide-based strategies, integrated with therapeutic and prophylactic treatment of human hosts, has led to eradication of malaria in several regions around the world. However, control strategies based on chemical insecticides are not always practical due to the economic cost, the characteristics of the region, mosquito breeding sites, etc. In addition, the ecological impact of massive insecticide treatment justi!es environmental and human health concerns about their application. Alternative, environment-friendly technologies are thus being explored to overcome such constraints. In this context, “biological control” strategies, based on the use of antagonistic organisms/microorganisms, have attracted a great deal of attention.