Larval habitats characterization and population dynamics of Culex mosquitoes in two localities of the Menoua Division, Dschang and Santchou, West Cameroon

Background Choosing an appropriate strategy for mosquito vector control in an eco-climatic facies requires knowledge on vector ecology including population dynamics of species and productivity of the breeding sites. The aim of this study was to characterize Culex mosquitoes breeding places and to determine their population dynamics in two localities (Dschang and Santchou) separated by a forest cliff in the West Region of Cameroon. Field surveys were conducted from November 2019 to June 2020 in Dschang and Santchou. Mosquito breeding sites were georeferenced, and for each breeding site, physical parameters were measured and immature stages were collected. The collected immatures were reared in the laboratory until adult stage. Adult mosquitoes were identified using a stereomicroscope and morphological identification keys. Results A total of 44 breeding sites were identified: 24 in Dschang and 20 in Santchou. They were grouped into seven types and were mostly shallow, close to human dwellings, sunny, with organic matters and of anthropogenic nature. A total of 2706 mosquitoes belonging to four genera were identified. Culex genus was the most represented (90.4%) and was made up of Culex pipiens s.l. (61.79%), Culex duttoni (23.17%) and Culex (Culiciomyia ) sp. (05.46%). High abundance of Culex species was observed in Santchou (52.71%) compared to Dschang (47.28%), while Dschang ( S = 3; H = 0.87; D = 0.54) recorded the greatest diversity compared to Santchou ( S = 2; H = 0.23; D = 0.11). Conclusions The proliferation and persistence of Culex mosquitoes independently of the breeding sites and localities might be attributable to the poor environmental management which favor the creation mosquito breeding sites. This study highlights the fact that prompt sanitation measures could be undertaken in these two localities to reduce mosquito abundance and the risk of vector-borne diseases.