Figure 1.

Schematic overview of experimental design. WT (Wolbachia+, purple) and Tet (Wolbachia-, red) lines of Culex quinquefasciatus mosquitoes were subject to three levels of larval competition stress (low, medium, high), with higher competition producing adult mosquitoes with smaller body size (A). Mosquito fitness (larval development time, pupation, and adult eclosion rates) were determined for mosquitoes from each experimental treatment (B). Genomic DNA was isolated from whole mosquitoes (collected at 5 days post-eclosion) and used in a SYBR green-based qPCR assay to compare Wolbachia density across the three WT treatments (C). Adult female mosquitoes from each of the six treatments were orally challenged with WNV (strain FLO3-FL2-3) via oral infection to determine whether competition and/or Wolbachia infection altered the course of infection (D). WNV infection in mosquito tissues (bodies, legs, and saliva all at 14 days post-infection) was evaluated via plaque-forming assay to assess the impact of Wolbachia infection and competition stress on mosquito susceptibility to WNV infection, and rates of WNV dissemination and transmission (E).