August 20th is World Mosquito Day, a day that commemorates Sir Ronald Ross’s demonstration in 1897 that a female anopheline mosquito is responsible for transmitting malaria to approximately half the world’s human population. Though the use of quinine to treat malaria provided some relief, his discovery paved the way for the development of vector control interventions targeting mosquitoes that reduced its spread and eventually eliminated it from hundreds of countries.
Dr. Ross had conducted trials with Culex (possibly Cx. fatigans) fed on birds infected with bird malaria, Protesoma relictum (now Plasmodium relictum) in 1894 noting that the plasmodium developed in the mosquito gut. This led him to suspect the same might happen with malaria, which he later confirmed through trials on human subjects.