Vector competence of three Venezuelan mosquitoes (Diptera : Culicidae) foran epizootic IC strain of Venezuelan equine encephalitis virus

Experimental studies were undertaken to evaluate the vector competence of s elected mosquito species [Aedes taeniorhynchus (Wiedemann), Culex declarato r Dyar and Knab, and Mansonia titillans (Walker)] from northwestern Venezue la for the epizootic (IC) strain of Venezuelan equine encephalitis (VEE) vi rus that was responsible for the 1995 outbreak of VEE in this area. Ae. tae niorhynchus was highly susceptible to infection (94% of 35), and 89% had a disseminated infection. Virus-exposed Ae. taeniorhynchus that refed on susc eptible hamsters readily transmitted virus, confirming that this species wa s an efficient vector of VEE virus. In contrast, only 1 of 28 (4%) Cx. decl arator was infected, and that individual did not develop a disseminated inf ection, Ma. titillans was moderately susceptible (3 of 8 infected, 38%), an d 2 (25%) of these had a disseminated infection. These data indicate that A e. taeniorhynchus was an important epizootic vector during the 1995 VEE out break in Columbia and Venezuela.