Extraction, Phytochemical
Analysis, GC-MS Characterization and Larvicidal Activities of Leaf Extracts of Leucas
aspera and Xanthium strumarium on Spodoptera Larva
Nagarathinam T., Raja Rajeswari A. and Umamaheswari S.
Res. J. Biotech.; Vol. 20(11); 241-248;
doi: https://doi.org/10.25303/2011rjbt2410248; (2025)
Abstract
The indiscriminate use of synthetic insecticides in agriculture has led to ecological
imbalance and resistance in pests like Spodoptera species. The present study investigates
the extraction, phytochemical composition, characterization and larvicidal activities
of leaf extracts of Leucas aspera and Xanthium strumarium against Spodoptera larvae,
a major agricultural pest. Aqueous and ethanol extracts were prepared from fresh
leaves using Soxhlet extraction. Preliminary phytochemical screening revealed the
presence of bioactive compounds such as alkaloids, flavonoids, tannins, saponins
and terpenoids. Characterization of the extracts was carried out using Gas Chromatography–Mass
Spectroscopy (GC-MS) and Fourier Transform Infrared Spectroscopy (FT-IR) to identify
functional groups associated with insecticidal activity.
Larvicidal bioassays were conducted using two concentrations (50 and 100 μg) under
laboratory conditions and both extracts demonstrated significant dose-dependent
mortality of Spodoptera larvae. Among the two, Xanthium strumarium extract showed
higher larvicidal potential. These findings suggest that Leucas aspera and Xanthium
strumarium leaf extracts possess potent phytochemicals with promising biocontrol
potential and can be considered as eco-friendly alternatives to synthetic pesticides
in integrated pest management (IPM) programs.
