Wild caught females of Aedes normanensis from Mataranka in the Northern Territory were fed on new born mice intracerebrally inoculated with Ross River (RR) virus isolated from the Northern Territory. Classic RR virus symptoms were produced in litters of new born mice from five to eight days after exposure to the infected mosquitoes. Tests on the mice showed cytopathic effects and the presence of alpha virus. Eggs laid by the caged mosquitoes reared to adults failed to show any evidence of transovarial transmission at least at the 0.46% level of individuals examined.