Characterization of mosquito larval habitats and spatio-temporal variation of culicidae fauna in seaport environment of Cotonou, Benin

Mosquitoes are major vectors of several diseases such as dengue, malaria, and others. Their presence and diversity directly influence epidemic risks. Climate change and urbanization have promoted the expansion of mosquitoes and their adaptation to new habitats. The objective of this study is to characterize the larval habitats of three mosquito species (Aedes, Culex, and Anopheles) in the Port of Cotonou and aims to provide information for mosquito control in a highly anthropized environment. The study was conducted at the Port of Cotonou between June 2023 and May 2024. Monthly captures of adult mosquitoes were carried out using BG sentinel and BG Pro traps at nine sites to measure specific density variation. Additionally, larvae were sampled in natural habitats (puddles, marshes) and artificial habitats (tires, gutters, flower saucers). The larvae were then reared in an insectarium and morphologically identified using specific identification keys. In total, 4,773 mosquitoes belonging to five genera and eight species were captured, with Culex quinquefasciatus, Aedes aegypti, and Anopheles gambiae being the dominant species. Specific diversity was low, and the most common larval habitats were used tires for Aedes, puddles for Anopheles, and gutters for Culex. A significant ecological plasticity was observed in these species, adapting to unconventional habitats in the absence of their preferred breeding sites. The study reveals a low specific diversity of mosquitoes in the Port of Cotonou, dominated by three species. Effective mosquito management, particularly of larval habitats, is crucial to reducing the epidemic risks of the diseases they vector. Environmental and behavioral measures are recommended to limit breeding habitats, particularly the management of used tires and stagnant water containers.