Biological control of mosquito larvae using naiad of ruddy marsh skimmer Crocothemis servilia

The naiads of Crocothemis servilia (Drury) feed only on larvae of Culex quiniquefasciatus and both larvae and pupae of Aedes aegypti under laboratory condition. It prefers 2^nd instar larva over other instars of C. quiniquefasciatus and for 3^rd instar larvae of A. aegypti. These exhibited higher predation rate during day time. The diurnal clearance rate was significantly higher than the nocturnal one for both the species. Maximum clearance rate was observed during first hour of predation. Results indicate that C. servilia could be used as a potential biocontrol agent against mosquito larvae.