Dissemination barriers to Ross River virus in Aedes vigilax and the effects of larval nutrition on their expression

Effects of larval nutrition on vector competence of the mosquito Ae(les vig ilax (Skuse) (Diptera: Culicidae) from Townsville, north Queensland, for Ro ss River virus (RR) were examined. Larvae were reared on three different di ets to create three significantly different size classes of adult mosquito. These were fed on serial dilutions of RR and then sampled on alternate day s so the progression of the virus through the mosquito could be examined. N o differences of vector competence could be attributed to larval nutrition. Barriers to infection and the correlation between infection rate, viral ti tre and transmission of RR by Ae, vigilax were also examined. The mesentero nal barrier was the only infection barrier expressed. No correlation betwee n viral titre and transmission was detected, but a strong correlation was f ound between salivary gland infection and transmission rate. From this it w as possible to estimate that 98.7 +/- 1.3% of Ae. vigilax with infected sal ivary glands transmit RR.