Comparative susceptibility of five species of Toxorhynchites mosquitoes to parenteral infection with dengue and other flaviviruses.

Five species of colonized Toxorhynchites mosquitoes were compared for relative susceptibility to parenteral infection with the four dengue serotypes and St. Louis and Japanese encephalitis viruses. Tx. amboinensis, Tx. brevipalpis, Tx. rutilus, and Tx. splendens were equally susceptible to infection with the dengue viruses, while Tx. theobaldi was relatively resistant to infection with those viruses. All five mosquito species were equally susceptible to infection with the encephalitis viruses. The intensity of immunofluorescence in head squashes was slightly less in Tx. brevipalpis infected with the dengue viruses as compared to the other three mosquito species susceptible to those viruses. Immunofluorescence was also less in Tx. theobaldi infected with the encephalitis viruses as compared with all the other mosquito species.