Getah virus in Aedes vexans nipponii and Culex tritaeniorhynchus: vector susceptibility and ability to transmit

Vector competences of Aedes (Ae.) vexans nipponii (nip.) and Culex (Cx.) tritaeniorhynchus to Getah virus were assessed by using a membrane feeding technique. The Getah virus was present at high titer in both species of mosquitoes after 21 days of extrinsic incubation at 28 degrees C. Infection rates on 21 post-feeding were 100 per cent (4/4) for Ae. vexans nip. at a virus dosage of 10(5.3) PFU/ml and 60 per cent (3/5) for Cx. tritaeniorhynchus at similar virus dosage. More than 10(3.5) PFU of virus was detected in salivary glands of both species of mosquitoes on day 21 of extrinsic incubation. Forty percent (2/5) of Ae. vexans nip. transmitted the virus into serum-agar after ingesting 10(4.3) PFU/ml of virus blood mixture. In experiments with Cx. tritaeniorhynchus ingesting 10(7.5) PFU/ml of virus blood mixture, 57 per cent (4/7) were able to transmit the virus to suckling mice and 59 per cent (10/17) transmitted the virus into serum-agar.