Horizontal and vertical transmission of Japanese encephalitis virus by Aedes japonicus (Diptera: Culicidae).

Aedes japonicus (Theobald) was evaluated for competence as a vector of Japanese encephalitis virus and for its ability to transmit the virus vertically to its F1 larvae. Ae. japonicus supported the growth of the virus at 20 and 28 degrees C after feeding on a virus-blood mixture of 10(6.2) plaque forming unit (PFU)/ml. This species was able to transmit the virus to suckling mice after feeding on a virus-blood meal (10(6.2) PFU/ml) or a viremic chick (10(3.7) PFU/ml). Vertical transmission of the virus in Ae. japonicus was demonstrated with a minimum infection rate of 0.7%.