Species complexes comprising morphologically indistinguishable biological species that are reproductively isolated, are of common occurrence among anophelines. A list of anopheline species complexes identified so far in the world has been given. To demonstrate the importance of species complexes in malaria control, we report the Anopheles culicifacies complex as a case study. An. culicifacies is a major vector of malaria in India and neighbouring countries. This complex comprises four sibling species, A, B, C and D. Stratification of U.P. state and district Allahabad has been shown taking into consideration the biological differences among sibling species, viz., sibling species composition and vectorial potential- species B is a non-vector while others are vectors. To achieve cost effective vector control, microlevel stratification at least at the block level has been suggested. Implications of differential responses of sibling species to DDT and malathion in field operations have been discussed. To achieve selective and sustainable control, and to reduce the unnecessary selection pressure of insecticides, an insecticide spray strategy to control An. culicifacies has been provided.