Introduction: Mosquitoes (Diptera: Culicidae) are primary vectors of public health importance in the Sahelian region of Northeastern Nigeria. This study evaluated the prevalence, species composition, and ecological predictors of mosquito distribution across diverse anthropogenic and natural habitats in Jere Local Government Area (LGA), Borno State. 

Methods: A cross-sectional survey was conducted across 15 sampling sites stratified into riparian, agricultural, and peri-urban zones. Larvae were collected using standard dipping methods, while adults were sampled using Pyrethrum Spray Catches (PSC) and CDC Light Traps. Morphological keys were used for species identification. Linear regression modeling was fitted to identify environmental predictors of larval density, and the Shannon-Wiener Diversity Index (H') was calculated to evaluate biodiversity shifts across life stages.

Results: A total of 676 mosquito specimens were collected (419 larvae and 257 adults). Five species across three genera (Culex, Anopheles, and Aedes) were identified. Culex quinquefasciatus was the dominant species, accounting for 50.1% of larvae and 72.5% of adults, followed by Anopheles gambiae s.l. (24.3% larvae; 21.0% adults), Anopheles arabiensis (13.1% larvae), Aedes aegypti (7.0% larvae; 4.5% adults), and Anopheles pharoensis (5.5% larvae). Species prevalence varied significantly by habitat type (ꭕ2 = 294.59, df = 6, p < 0.0001). Linear regression demonstrated that stagnant gutters were the strongest predictor of larval density (B = 2.750, p < 0.001), while pools near communal boreholes acted as persistent year-round reservoirs. Biodiversity analysis revealed a sharp decline in species diversity from larvae (H' = 1.30) to adults (H' = 0.71), indicating a severe ecological survival bottleneck in human-altered urban environments. 

Conclusion: Anthropogenic drainage systems and unmanaged water points are the primary drivers of vector proliferation in Jere LGA. Targeted Larval Source Management (LSM), focusing on urban drainage engineering and desilting, is critical for effective vector control in this Sahelian setting