Dry season refugia breeding ecology of mosquitoes (Diptera: Cullicidaae in Minna, North central Nigeria

Abstract

This study was carried out in Minna, Nigeria, to elucidate the dry season breeding ecology of mosquitoes in the area thus, providing a basis for all-year-round effective implementation of informed larviciding interventions. Mosquito larvae were sampled bi-weekly between the hours of 0800 and 1100 from randomly selected larval breeding habitats in the city, using a 3S0 mL capacity Dipper. The physical characteristics of the selected habitats were evaluated and related to larval productivity. The results indicated that Anopheles mosquitoes constituted SS.OO% of all larvae collected, followed by Culex (36.29%) and Aedes (17.49%). The patterns of mean monthly density distribution of the three mosquito Genera were similar, i.e., decreasing significantly (p<O.OS) from the beginning to the end of the dry season. The mosquito types showed significant (p<O.OS) preferences for certain habitats, with Anopheles and Aedes preferring the Drains (24.40±5.13 and 14.20±S.12 larvae/sampling day, respectively) and Culex mosquitoes encountered more frequently in the Swamps (l6.80±6.22 larvae/sampling day). The Drains were the most productive habitats, accounting for over SO% larval production during the period, distantly followed by the Swamp (31.60±16.38 larvae/sampling day) while, the densities oflarvae in the Wells and Rivers were significantly low (7.40±7.79 and 3.40±S.24 larvae/sampling day, respectively). Again, in terms of physical attributes, the Drains were the most ideal habitat for larval development, been relatively small (diameter = 2.30±0.00 m); most shallow (depth = 0.14±0.01 m); warmest (27.S2±0.48°C) and nearest to human habitations (2.80±0.00 m). The epidemiological implications of these results were discussed and concluded that targeting dry season larviciding interventions at the productive larval breeding habitats will go a long way in reducing the menace of mosquito-borne diseases in Minna.