A laboratory-adapted and a clinical isolate of dengue virus serotype 4 differently impact <i>Aedes aegypti</i> life-history traits relevant to vectorial capacity

As dengue virus (DENV) cases rise globally, vector control strategies targeting <i>Aedes aegypti</i> remain essential to public health. The effectiveness of these interventions depends on understanding how viral strains interact with mosquito biology. We show that two phylogenetically distinct DENV serotype 4 strains-one laboratory-adapted, one recently isolated-differentially affect <i>Ae. aegypti</i> traits, such as fertility, flight capacity, and infection dynamics. These traits are linked to mosquito fitness and vector competence, and our results show that sequence variation can shape mosquito-virus interactions. The lab strain enhanced flight capacity at key time points, potentially aiding transmission, while the clinical isolate reduced fertility independently of viral dose. Infection prevalence and sensitivity to viral dose also differed between strains. These findings highlight how viral genotype influences mosquito performance and transmission potential. Incorporating viral genetic diversity into arbovirus studies can improve disease spread models and inform mosquito-based control strategies.