Life-history divergence in Aedes aegypti (Diptera: Culicidae) aligns with Kenya’s dengue landscape

Abstract

Dengue outbreaks in Kenya are concentrated along the coast despite widespread ecological suitability for Aedes aegypti inland, suggesting that transmission risk is shaped by more than climate alone. Population-level variation in mosquito life-history traits—interacting with vector competence, climate-driven abundance, and socio-ecological factors—may contribute to this heterogeneity, yet direct comparative data of differences in life history traits across Kenyan populations remain scarce. Using a common-garden experiment with minimally colonized populations, we compared early survival and developmental timing among Ae. aegypti from coastal Mombasa, inland Kisumu, and a laboratory-adapted Mexico colony under identical insectary conditions. Substantial colony-level differences persisted: Mombasa mosquitoes showed higher early-stage success and faster development, Kisumu mosquitoes exhibited reduced early performance and slower development, and the Mexico colony maintained consistently high survival. Although derived from single field collections, these findings demonstrate that meaningful variation in key life-history traits can persist among Ae. aegypti colonies when evaluated under standardized conditions. Such differences may influence local population growth dynamics, but do not alone determine transmission risk. Incorporating population-specific mosquito biology into surveillance and modeling frameworks—alongside measures of vector competence, adult behavior, and human exposure—may improve spatial risk prediction and support more context-appropriate vector control strategies.