Vol. 8, Issue 4, Part A (2021)

Author(s): Sumitha V, Mini I and Laija S Nair

Abstract: Mosquitoes are the most important group of insects declared as major vectors for the transmission of life threatening diseases like malaria, filariasis, dengue fever, Japanese encephalitis, chikungunya fever etc. Now-a-days, the control and eradication of mosquitoes with synthetic insecticides raises a major problem, because of the development of resistance to chemicals by the mosquito as well as environmental pollution. Plant products may be used as an alternate source in control of mosquitoes from time immemorial. The present investigation focused on the evaluation of the larvicidal activity of methanolic extract of leaf of H. capitata against Culex quinquefasciatus mosquito followed by GC-MS analysis for the assessment of phytocompounds in the extract. Larvicidal bioassay exhibited 93.3 ± 11.54% of larval mortality at a concentration of 25 mg ml-1 (P < 0.05) and the LC 50 was found to be 11.15 mg ml-1. About nine chemically diversified volatile terpene compounds were detected and quantified. The major compounds present in the extract were Methyl Commate –D (55.50%) followed by phytol (16.51%), squalene (13.28%) and tocopherol (5.60%) The significant larvicidal activity may be attributed to the synergistic action of the detected phytochemicals especially phytol, squalene and tocopherol. The methanolic leaf extract of H. capitata may be used as an effective biolarvicide for the Culex quinquefasciatus mosquito.