Seasonal Variation in Mosquito Larval Breeding Sites in Urban and Peri-Urban Areas of Abeokuta, Ogun State

Effective malaria vector control requires a thorough understanding of the spatial and seasonal dynamics of Anopheles mosquito larval habitats in urban and peri-urban settings. This longitudinal entomological study characterised seasonal variation in mosquito larval breeding sites in Abeokuta, Ogun State, Southwest Nigeria. Larval surveys were conducted monthly for 12 months across 15 randomly selected transects in urban and peri-urban zones. All water bodies including open drains, pits, tyres, flower pots, and construction sites were sampled using standard larval dipping techniques. Anopheles and Culex larvae were differentiated morphologically at the third and fourth instar stages. A total of 3,240 larvae were collected, with Anopheles gambiae accounting for 41.2 percent of Anopheles specimens. Breeding site density was threefold higher during the rainy season. Open drainage channels and temporary ground pools were the most productive habitats. Urban core areas showed higher Culex densities, while peri-urban zones harboured significantly more Anopheles. The study recommends targeted larval source management, drainage maintenance, and community mobilisation for environmental sanitation as complementary vector control strategies in Ogun State. Keywords: larval breeding sites, Anopheles gambiae, seasonal variation, larval source management, Abeokuta.