Diversity of aquatic insects in irrigated rice fields of South India with reference to mosquitoes (Diptera: Culicidae)

Abstract

Rice field supports a variety of living organisms as algae, macroinvertebrates, vertebrates and a plethora of microorganisms and also it supports vector species of mosquitoes. In this study, we examined the diversity and distribution of aquatic insects in irrigated rice fields and compared the colonization pattern of aquatic insect predators with mosquito larvae. Diversity indices were analyzed for aquatic insects. A total of 25656 individuals were collected during this study belong to 35 morpho-species of aquatic insects. The highest diversity was observed in site 4 (Chellampatti). Among aquatic insects, the dipterans were occupied the highes percentage (94%). Trophic analysis revealed that the collectors were dominated over (80%) than other functional groups. The colonization pattern showed that co-existent pattern was observed between predators and collectors, which indicate that larval abundance of mosquitoes can be controlled naturally by aquatic insect predators. Thus, aquatic insects in rice field are probably a crucial factor in the control of mosquito larvae. This study suggests that natural practice like integrated pest management (IPM) is necessary to ecosystem health as well as control of mosquito larvae.