Microspatial partitioning of insect-specific viromes and dengue virus transmission risk by Aedes aegypt i in Puerto Rico

Mosquito-borne arboviruses remain a major global health threat. Although insect-specific viruses (ISVs) may influence arbovirus transmission across geographic regions, their diversity within Aedes aegypti populations at microspatial scales remains poorly understood. We hypothesized that local environmental variation shapes the A. aegypti core virome, producing distinct ISV profiles in rural and urban populations in Puerto Rico. Metatranscriptomic RNA sequencing of F0 mosquitoes identified thirteen ISVs with habitat-specific virome composition. Partitiviridae was the dominant viral family, while Humaita-Tubiacanga virus (HTV) and Phasi Charoen-like phasivirus (PCLV) exhibited the highest abundance, persistence, and prevalence in urban laboratory colonies. Urban A. aegypti also showed significantly higher dengue virus-1 (DENV-1) infection rates than rural populations, although saliva positivity remained low and did not differ significantly between the two groups. These findings indicate that microspatial ecological variation shapes the A. aegypti virome, but the association of HTV/PCLV with DENV-1 transmission risk is likely multifactorial and nuanced.