Larvicidal Activity of Isodon japonicus var. glaucocalyx (Maxim.) H.W.Li Essential Oil to Aedes aegypti L. and its Chemical Composition
Purpose: To determine the larvicidal activity of the essential oil derived from Isodon japonicus var. glaucocalyx (Maxim.) H.W.Li (Labiatae) aerial parts at flowering stage against the larvae of Aedes aegypti L.
Methods: The essential oil of I. japonicus var. glaucocalyx aerial parts was obtained by hydrodistillation and analyzed by gas chromatography (GC) and gas chromaotography-mas spectrometry (GC-MS). The activity of the essential oil was evaluated, using World Health Organization (WHO) procedures, against the fourth larvae of A. aegypti for 24 h, and larval mortality recorded at various essential oil concentrations ranging from 12.5 - 200 µg/mL.
Results: A total of 34 components of the essential oil of I. japonicus var. glaucocalyx were identified. The principal compounds of the essential oil were thujone (9.65 %), morillol (8.14 %), caryophyllene oxide (7.68 %), β-caryophyllene (7.60 %), α-terpineol (7.22 %), 1,8-cineole (7.09 %), linalool (5.56 %), Z-caryophyllene (5.10 %) and γ-eudesmol (4.71 %). The essential oil exhibited larvicidal activity against A. aegypti with a median lethal concentration (LC50) of 40.82 µg/mL.
Conclusion: The findings indicate that the essential oil of I. japonicus var. glaucocalyx aerial parts has potentials for use in the control of A. aegypti larvae and may be useful in the search for newer, safer and more effective natural compounds for use as larvicides.
Keywords: Isodon japonicus var. glaucocalyx, Aedes aegypti, Larvicidal activity, Mosquito, Essential oil
Submission of a manuscript to this journal is a representation that the manuscript has not been published previously and is not under consideration for publication elsewhere.
All authors named in each manuscript would be required to sign a form (to be supplied by the Editor) so that they may retain their copyright in the article but to assign to us (the Publishers) and its licensees in perpetuity, in all forms, formats and media (whether known or created in the future) to (i) publish, reproduce, distribute, display and store the contribution, (ii) translate the contribution into other languages, create adaptations, reprints, include within collections and create summaries, extracts and/or abstracts of the contribution, (iii) create any other derivative works(s) based on the contribution, (iv) to exploit all subsidiary rights in the contribution, (v) the inclusion of electronic links from the contribution to third party material where-ever it may be located, and (vi) license any thrid party to do any or all of the above.