Distribution and Abundance of Anopheles Mosquito Species in Relation to Malaria Transmission in Ondo State, South West Nigeria

Accurate entomological surveillance of Anopheles mosquito vectors is essential for understanding malaria transmission dynamics and designing effective vector control strategies. This study investigates the distribution and species abundance of Anopheles mosquitoes in relation to malaria transmission intensity in Ondo State, South West Nigeria. A cross-sectional entomological survey was conducted across rural, peri-urban, and urban communities in Akure, Owo, and Okitipupa Local Government Areas. Adult mosquitoes were collected using Centers for Disease Control light traps and pyrethrum spray catches over six weeks during the peak transmission season. Specimens were morphologically identified using standard taxonomic keys, and a subset was dissected to assess parity rates and sporozoite infectivity. Larval habitats were mapped and characterised in each study community. Current entomological data from 2020 to 2024 confirm Anopheles gambiae sensu lato and Anopheles funestus as the dominant malaria vectors in southwestern Nigeria, with biting rates correlated with proximity to stagnant water bodies and urban green spaces. This study quantifies species-specific biting densities and correlates vector data with malaria prevalence records from health facilities. Findings will inform the Ondo State Malaria Elimination Programme on priority communities for indoor residual spraying and larval source management. Keywords: Anopheles mosquitoes, malaria vectors, entomological surveillance, Ondo State, sporozoite rate.