Impact of Environmental Factors on Anopheline Larval Density

Abstract

Aim: This study aim is to determine the impact of environmental factors on mosquito larval density breeding within Lugbe and Gosa communities. Study Design: Anopheline mosquito larval breeding sites were identified and characterized in both dry and wet seasons. Samplings were done in the morning (08:00-12:00 h) or afternoon (14:00-17:00 h) for about 45 mins at each larval habitat. Larval sampling was done using USAID approved techniques. Place and Duration of Study: The Presidential Malarial initiative PMI/USAID - funded Insectary Laboratory at Nasarawa State University, Keffi/six (6) Months. Methodology: Standard 350 mL dipper for large water bodies; ladle and plastic pipettes for small water bodies where dippers will not be effective, once forth nightly. Water collected were emptied into a white basin and checked for mosquito larvae. The Anopheline larvae were passed through a 100 mesh sieve and stored in labelled container. Environmental characteristics of each larval habitat were measured and recorded during larval collection. The Environmental data determined included habitat hydrological variables. Data on the amount of rainfall and humidity was gotten from Nigerian Meteorological Agency (NIMET). The temperature was determined in-situ using the mercury – in – glass thermometer. Results: The study findings indicate that larval density was seen to be higher in Lugbe than in Gosa. This may not be unconnected to the fact that more habitats were found in Lugbe than in Gosa. Also, it is evident from the result that temperature, rainfall and relative humidity have various degrees of impact on larval density with temporary waters having higher larval density.  In this study, Principal Component Analysis (PCA) extracted two significant Principal Components with eigenvalues > 1, explaining about 69.50% and 61.23% of the total variance in corresponding larvae density. Conclusion: This study, has shown that targeting the Anopheline larvae can be an effective tool in the fight against Malaria. Moreover, temperature, relative humidity and rainfall have a great effect on the Anopheline larval densities in Lugbe and Gosa areas of the Federal Capital Territory (FCT).