Changing seasons have effect on development of Wuchereria larvae. The effect of seasonal fluctuations on the development were assessed by experimental infection to Culex quinquefasciatus from a human volunteer (microfilaria (mf) carrier). Study indicates that the rainy season provides optimal conditions for transmission of Wuchereria in terms of minimum time span for the development of mf into infective L₃ larvae without any apparent loss of parasitic load during the process of development. There exists a robust relationship between ingestion of mf, production of L₃ and mf density in human blood which is a crucial determinant within the transmission dynamics of filaria.