Purpose: To evaluate the larvicidal activity of the essential oil of Salvia plebeian R.Br. (Labiatae) aerial
parts against the larvae of
Aedes aegypti
L.
Methods: The essential oil of S. plebeian aerial parts was obtained by hydro-distillation and analyzed
by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The essential oil
was evaluated for larvicidal activity using World Health Organization (WHO) procedures, against the
fourth larvae of
A. aegypti within 24 h, and activity was recorded for various concentrations of the
ranging from 12.5 – 200.0 μg/mL.
Results: A total of 33 components of the essential oil of S. plebeian were identified. The major
compounds of the essential oil were caryophyllene oxide (15.54 %), γ-eudesmol (14.03 %), τ-cadinol
(10.21 %), calamenene (9.63 %), copaene (5.70 %), γ-cadinene (5.30 %), cadalene (5.28 %), α-
muurolene (5.19 %), ledol (5.14 %) and α-cadinol (5.08 %). The essential oil exhibited larvicidal activity
against
A. aegypti at a median lethal concentration (LC
50) of 46.26 μg/mL.
Conclusion: The findings indicate that the essential oil of S. plebeian 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 as larvicides.
