Otarigho, B. and Morenikeji, O.A (2013) Molluscicidal Effects of Aqueous and Ethanolic Extracts of Lemongrass (Cymbopogon Citratus) Leaf against the Different Developmental Stages of Biomphalaria pfeifferi NY Sci J 2012;5(8):70-77]. (ISSN: 1554-0200).

Abstract

The molluscicidal activities of aqueous and ethanolic extracts of Cymbopogon citratus leaf against adult, juveniles and egg-masses of Biomphalaria pfeifferi were investigated. Ten adults each of Biomphalaria pfeifferi were exposed to a serial dilution of 40, 80, 160, 240, 320, 400, and 480ppm distilled water extracts and 20, 40, 80, 160, 240, 320ppm ethanolic extracts. Twenty juveniles of uniform size each were exposed to 8, 20, 28, 40, 80, 120, and 160ppm of aqueous and ethanolic extracts. Thirty eggs each were exposed to 8, 20, 28, 40, 60, 80, and 100ppm of aqueous and ethanolic extracts. Exposure period was 24hrs for adult and juvenile stage while 48 hrs for the egg stage. The lethal concentration LC50 against eggs, juveniles and adults were 73.27, 64.60 and 140.74ppm respectively for Cymbopogon citratus aqueous extract, 42.85, 43.87 and 61.79ppm respectively for Cymbopogon citratus ethanolic extract. The lethal concentration LC90 against eggs, juveniles and adults were 182.37, 244.42 and 254.92ppm respectively for Cymbopogon citratus aqueous extract, 113.20, 166.31 and 159.47ppm respectively for Cymbopogon citratus ethanolic extract. The plant extracts caused significant mortality rates of the different stages of B. pfeifferi (P<0.05). The result obtained show that Cymbopogon citratus is a promising plant molluscicide candidate and deserves further studies in order to identify and characterize its molluscicidal components.