Getah virus in several species of mosquitoes

Vector competence of Aedes (Ae.) vexans nipponii (nip.) and Culex (Cx) tritaeniorhynchus for Getah virus was compared after incubation at 28 degrees C and 20 degrees C. Marked differences existed between Ae. vexans nip. strains Sapporo and Cx tritaeniorhynchus strain Kyoto in infection and transmission rates following ingestion of blood meals containing several concentrations of Getah virus. Simultaneous comparison of infectivity also revealed that infection rates of Ae. vexans nip. strains Sapporo (74%) and Shizunai (68%) were higher than those of Cx tritaeniorhynchus strain Kyoto (44%). No significant differences were seen in infection rates between three strains of Cx tritaeniorhynchus or between two strains of Ae. vexans nip. Getah virus propagated and was transmitted in Ae. vexans nip. as rapidly at 20 degrees C as at 28 degrees C. Following seven days' incubation both at 20 degrees C and 28 degrees C, Ae. vexans nip. was capable of transmitting the virus. 14 days' incubation at 20 degrees C were needed for Cx tritaeniorhynchus to acquire the same capability. Ae. japonicus, Ae. aegypti, Ae. albopictus, Cx pipens pallens, Armigeres subalbatus and Tripteroides bambusa were also susceptible to Getah virus infection.