Susceptibility of Aedes albopictus and Culex tritaeniorhynchus (Diptera: Culicidae) collected in Miki City, Japan, to Dirofilaria immitis (Spirurida: Filariidae).

Female Aedes albopictus (Skuse) and Culex tritaeniorhynchus Giles from Miki City, Japan, were examined for susceptibility to infection by Dirofilaria immitis. Third-stage larvae were detected from day 7 in 10-40% of Ae. albopictus and from day 10 in 20-60% of Cx. tritaeniorhynchus, irrespective of microfilarial intake, which varied from 500 to 15,000 microfilariae per ml. The number of third-stage larvae in the labium usually varied from one to three per mosquito up to day 21, confirming the ability of these mosquitoes to transmit D. immitis.