The main function of morphological taxonomy of anophelines is to permit accurate identification of species, but infraspecific variation also is important. Species and subspecies are briefly defined, and sibling species-groups are more fully discussed. There is need to coordinate the findings of classical taxonomy and those of chromosomal taxonomy. The number of species of Anopheles known in the world has doubled in 30 years and now stands at about 350, but the rate of discovery of new species shows no obvious decline. Many species-groups need further study, and knowledge of the distribution and variation of their member species is often fragmentary.

Widespread vector species show geographic variation in morphology and in vector status. Examples are given to show that a study of the correlation between infraspecific variations in morphology and vector status holds promise of future advances in malaria control.