SUSCEPTIBILITY OF SELECTED STRAINS OF AUSTRALIAN MOSQUITOS (DIPTERA, CULICIDAE) TO RIFT-VALLEY FEVER VIRUS

We evaluated the ability of selected strains of the Australian mosquit oes, Aedes notoscriptus (Skuse),Ae, vigilax (Skuse), Culex annulirostr is Skuse, and Cx. quinquefasciatus Say, to function as potential vecto rs of Rift Valley fever (RVF) virus, should that virus be introduced a ccidentally into Australia. After feeding on a hamster with a viremia of 10(7) plaque-forming units/ml of blood, Ae. notoscriptus and Cx. an nulirostris were the most susceptible, with infection rates of 86 and 55%. respectively. Female Ac, vigilax and Cx. quinquefasciatus also we re susceptible, with infection rates of 38 and 30%, respectively. All of these species transmitted RVF virus by bite 7-10 d after intrathora cic inoculation, and all, except Cr, quinquefasiatus (not tested), tra nsmitted RVF virus 10-16 d after oral exposure, The presence of compet ent mosquito vectors for RVF virus in Australia indicates the potentia l for RVF virus epizootics to occur should this virus be introduced in to Australia.