LAUSR

Abstract The present study undertakes the evaluation of mosquito-larvicidal activity of phytochemical extracts of Halymenia palmata. The larvicidal activity of methanolic crude extract of seaweed, H. palmata (HPMe) and its fractions (Hpf-1 and Hpf-2) fractioned by chromatographic technique were assessed against the mosquito larvae of Aedes aegypti. The maximum lethality was recorded by Hpf-2 with LC50 & LC90 values (μg/mL) 23.69 & 233.49 respectively, whereas, HPMe and Hpf-1 showed a moderate activity of: 42.73 and 95.48; 91.95 and 709.04 respectively. The GC–MS analysis of Hpf-2 revealed the presence of 20 bioactive compounds with two major peaks corresponding to Phytol and 2-propamine which may be responsible for mosquito-toxicity. The Hpf-2 treated mosquito larvae (A. aegypti) have shown the progressive deformities in the lateral hair. These findings provide an important baseline data on the mosquito-larvicidal activity of H. palmata although further studies are warranted.