Variation in susceptibility among colony strains of Culex tritaeniorhynchus to Japanese encephalitis virus infection.

The susceptibilities to Japanese encephalitis virus of eight strains of Culex tritaeniorhynchus, seven domestic and one from Taiwan, were studied quantitatively by the membrane feeding technique. Six of them, originated from the main islands of Japan (Honshu and Kyushu) and Okinawa, had moderate susceptibilities to the virus. One strain from Amami Island was slightly more susceptible than moderate strains and was sixfold more susceptible than Taiwan strain. The differences, were statistically significant, but too small to perform genetic analysis for the susceptibility of the mosquito to the virus.