Effect of Climatic Conditions and Water Bodies on Population Dynamics of the Dengue Vector, Aedes aegypti (Diptera: Culicidae)

BACKGROUND The population of mosquitoes is mainly influenced by the biotic and abiotic factors. Although Aedes aegypti was reported until 1960's in the Punjab, Pakistan, the population has increased dramatically since 2009 and caused severe epidemics in 2011 due to heavy floods and rains. Thus, this study was carried out to know the effect of biotic and abiotic factors on the population of Aedes aegypti. METHODS Mosquitoes were collected from fresh, sewage, and rain water ponds, fish ponds, rice fields, tyres, tree holes, and manmade storage containers present in and around residential homes twice during every winter (October-February), summer (March-June) and monsoon season (July-September) from marked rural areas. RESULTS More mosquitoes were collected in 2010 and 2011 due to floods than other years with heavy rains. High population (52.4%) was recorded during the rainy season due to high temperature (28-36 °C) and high relative humidity (up to 75%), while low population was recorded during the winter due to low temperature (< 5 °C) and low relative humidity (< 22%). Specimens were recorded indoors when outside temperature was below freezing point. Ae. aegypti was largely collected from tyres and urban areas mostly during the rainy season from small water containers. Years, months, seasons, temperature and relative humidity were statistically significant concerning the population dynamics of mosquitoes. CONCLUSION Abiotic factors (temperature & relative humidity) along with habitat have significant impact on population dynamics of mosquitoes.