In our efforts to control insect-borne diseases, we should know whether more than one species is capable of acting as an intermediary host and, if so, what ones. It is also of importance to determine the relative susceptibility of the different species. More than a hundred species of Anophelinae are now known, and of this number less than a third have been proved to be transmitters of malaria; the remaining species either have not been studied or evidence of their susceptibility is lacking. Beyond this, it has been shown that Anophelinae vary widely in their susceptibility to infection with the same malarial parasite. The same species may not be capable of acting as transmitter of all three types of human malarial parasite.
It is probable that the same species of Anophelinae may vary in its susceptibility to infection with the malarial parasite in different parts of the world and under