The mosquito Stegomyia albopicta is among the most important arbovirus vectors in the world, particularly for Dengue viruses. Their natural history suggests that biologically these viruses are highly adapted to their mosquito hosts and they were most likely mosquito viruses prior to becoming adapted to lower primates and humans. As well as being maintained by transmission among susceptible humans, Dengue viruses may also be maintained by vertical transmission in mosquitoes during inter-epidemic periods. The larvae and mosquitoes of Stegomyia albopicta were used to identify the vertical transmission of the dengue virus in nature and to confirm the vectorial capacity concerning the Dengue virus type 2 infection. The minimum infection rate concerning S. albopicta infection with the Dengue virus was 1:36.45. In Brazil this was the first time that high minimum infection rates of vertical transmission of S. albopicta were detected in this species.Keywords: Dengue virus, vertical transmission, Stegomyia albopicta, vectorial capacity. Transmissão vertical natural de Stegomyia albopicta como vetor de dengue no BrasilResumo O mosquito Stegomyia albopicta está dentre os mais importantes vetores de arbovírus do mundo, particularmente para o Dengue virus. A história natural sugere que biologicamente esses vírus são altamente adaptados aos seus mosquitos vetores e foram, provavelmente, os vírus que infectavam mosquitos antes de se tornarem adaptados a primatas não humanos e humanos. Além de serem mantidos entre os homens susceptíveis, os Dengue viruses podem também ser mantidos pela transmissão vertical em mosquitos durante os períodos interepidêmicos. As larvas e mosquitos da espécie Stegomyia albopicta foram utilizados para a identificação da transmissão vertical do vírus dengue na natureza e para confirmar a capacidade vetorial em relação à infecção pelo DENV-2 infection. A taxa mínima de infecção em relação à infecção do S. albopicta com o Dengue virus foi de 1:36,45. No Brasil, esta é a primeira vez que altas taxas de infecção mínima da transmissão vertical de S. albopicta foram detectadas nessa espécie.Palavras-chave: Dengue vírus, transmissão vertical, Stegomyia albopicta, capacidade vetorial.

Dengue is a viral disease transmitted by mosquitoes and caused by four viral serotypes (DENV 1-4). This mosquito-borne disease is a major public health problem and a threat to more than 2.5 billion people, who live in endemic areas. Aedes aegypti is the primary vector of dengue in the Americas. The present study shows the susceptibility of a colony strain of A. aegypti to Dengue 2 virus (DENV-2). A. aegypti females from a laboratory colony were infected with DENV-2 using a membrane feeding technique. The engorged females were dissected on different days (3, 6,9, 12 and 15). The midguts, ovaries, carcasses and heads were separated. The samples were