Figure 4.

Culex pipiens selectively transmit WNV when exposed to both viruses through blood meal. (A) Schematic overview of the experimental design. (B, C) Bar graphs show the percent of USUV and WNV positive mosquito bodies and saliva of the total tested engorged mosquitoes at 14 days after blood meal. “U”, “W” and “UW” represent USUV, WNV and co-infectious blood meal, respectively. (+) and (n) indicate the numbers of viral positive samples and total numbers of the tested engorged mosquitoes, respectively. The results present cumulative numbers from three independent experiments (Table S4). Statistics were performed using Fisher's exact test. Asterisks (*) and (***) indicate significance at P < 0.05 and < 0.001, respectively; ns indicates no significant difference. (D) Viral genome copies of USUV and E, WNV in the infected mosquito bodies after either a single or co-infectious blood meal exposure. One-way ANOVA with Tukey's multiple comparison was used to compare the mean of the genome copies. Asterisk (*) indicates a significant difference (P < 0.05); ns indicates no significant difference. The cut-off value for USUV and WNV genomes copies was indicated by black dash lines.