This work was done as a research for the MPhil degree of the author at the University of Ruhuna, Sri Lanka, which was submitted in 2005. The title of the research project was "faunal diversity in rice fields under organic and inorganic based farming systems in wet zone of Sri Lanka". The main objectives of the said research were to compare the faunal diversity between two rice cultivation fields using organic and chemical based inputs. The research was supervised by Professor Asoka Gunawardena (University of Ruhuna) and Dr. Devaka Weerakoon (University of Colombo). The findings of this research were already published as several journal articles.