K Krishnappa1, K Elumalai. 1. Department of Zoology, Poompuhar College, Melaiyur, Nagapattinam District, Tamilnadu, India.
Abstract
OBJECTIVE: To investigate the larvicidal and ovicidal activities of acetone, benzene, hexane and methanol leaf extracts of Basella rubra and Cleome viscosa against dengue vector, Aedes aegypti. MATERIALS AND METHODS: Twenty five early third instar larvae of Aedes aegypti were exposed to various concentrations and were assayed in the laboratory by using the protocol of WHO 2005. The 24h LC50 values of the Basella rubra and Cleome viscosa leaf extracts were determined by probit analysis. The ovicidal activity was determined against Aedes aegypti to various concentrations ranging from 50-420 ppm under laboratory conditions. The hatch rates were assessed 48 h post treatment. RESULTS: The LC50 value of acetone, benzene, hexane and methanol leaf extracts of Basella rubra were 72.63, 53.62, 122.64 and 63.28 ppm, respectively. Cleome viscosa shows the LC50 values of 126.12, 82.43, 179.26 and 123.34 ppm, respectively. Among two plant solvents tested, Basella rubra extracts were found to be most significant ovicidal activity 100% egg mortality (zero hatchability) observed at 300 ppm and 420 ppm for Cleome viscosa. CONCLUSIONS: The crude extracts of Basella rubra and Cleome viscosa were an excellent potential for controlling Aedes aegypti mosquitoes.
OBJECTIVE: To investigate the larvicidal and ovicidal activities of acetone, benzene, hexane and methanol leaf extracts of Basella rubra and Cleome viscosa against dengue vector, Aedes aegypti. MATERIALS AND METHODS: Twenty five early third instar larvae of Aedes aegypti were exposed to various concentrations and were assayed in the laboratory by using the protocol of WHO 2005. The 24h LC50 values of the Basella rubra and Cleome viscosa leaf extracts were determined by probit analysis. The ovicidal activity was determined against Aedes aegypti to various concentrations ranging from 50-420 ppm under laboratory conditions. The hatch rates were assessed 48 h post treatment. RESULTS: The LC50 value of acetone, benzene, hexane and methanol leaf extracts of Basella rubra were 72.63, 53.62, 122.64 and 63.28 ppm, respectively. Cleome viscosa shows the LC50 values of 126.12, 82.43, 179.26 and 123.34 ppm, respectively. Among two plant solvents tested, Basella rubra extracts were found to be most significant ovicidal activity 100% egg mortality (zero hatchability) observed at 300 ppm and 420 ppm for Cleome viscosa. CONCLUSIONS: The crude extracts of Basella rubra and Cleome viscosa were an excellent potential for controlling Aedes aegypti mosquitoes.