In experiment 1, we studied CHIKV and DENV loads in siblings from single female x male pair crosses and calculated the heritabilities and genetic correlations of the loads. We then carried out RNAseq comparing two groups; families with the four highest and four lowest mean CHIKV loads. In experiment 2, we reared a separate set of mosquitoes from the same population and exposed them to CHIKV, DENV, or mock (uninfected cell culture control) infection through blood-feeding treatments and then dissected key tissues (midgut, carcass, salivary glands) at three timepoints post-infection (4, 7, 14). We then examined patterns of gene expression of the top candidate gene from the RNAseq analysis in experiment 1 across treatments and tissues x time. Created with BioRender.com.