Mosquito Larvicidal Activity of Fractionated Methanolic Extractof Rhizophora mucronata Stilt Root and Sesuvium portulacastrum against Dengue Larvae

To determine the larvicidal activity of fractionated methanolic extract of stilt root of Rhizophora mucronata and leaf of Sessuvium portulacastrum against dengue larvae. Fractionated methanolic extracts of stilt root of Rhizophora mucronata and leaf of Sessuvium portulacastrum were dissolved in dimethylsulfoxide (DMSO) to prepare a graded series of concentration. Batches of 25 early 4 th instars larvae of dengue were transferred to 250 mL enamel bowl containing 199 mL of distilled water and 1 mL of plant extracts (0.01-0.1 mg). Each experiment was conducted in three replicates. A control group consisted of 1 mL of DMSO and 99 mL of distilled water only. After 24 h, the percentage of mortality was identified with the formula: % of extraction= wt of the extract/wt of the plant material X 100. The fractionated leaf extracts showed maximum larvicidal activity fractionated extract 3 showed minimum level of LC 50 value (0.051±0.2 (0.41-0.602). Simultaneously, the fractionated stilt root extract of Rhizophora mucronata showed maximum larvicidal activity and (RF-2) showed minimum level of LC 50 value (0.51±0.29 (0.45-0.65). It can be concluded from the present study that, the fractionated methanolic extracts of stilt root of Rhizophora mucronata and leaf of Sessuvium portulacastrum against dengue larvae possess active compounds for development of larvicidal activity.