Aëdes leucocelaenus transmits yellow fever virus readily in the laboratory and has twice been found infected in nature.
Except in south Brazil this species is much less common than Haemagogus spegazzinii among day-biting sylvan mosquitos captured with human bait.
A. leucocelaenus has a wide distribution throughout the forested area of this country.
As a natural vector of jungle yellow fever in the northern part of Brazil it is of secondary importance when compared to H. spegazzinii.
* The studies and observations on which this paper is based were conducted with the support and under the auspices of the National Yellow Fever Service of Brazil and of the Yellow Fever Research Service, which was maintained jointly by the Ministry of Education and Health of Brazil and by the International Health Division of The Rockefeller Foundation.