Biological Control of Culex Mosquitoes Using Termite Soil Extracts as A Natural Larvicide

Termite mound soils represent biologically engineered microhabitats enriched with organic matter and microbial metabolites, yet their biochemical and bioactive potential remains underexplored. The present study investigated the phytochemical composition, biochemical profile, chromatographic characteristics, antimicrobial activity, and larvicidal efficacy of termite mound soil extracts prepared using solvents of varying polarity. Soil samples were collected from termite mounds located in Chennai, India, and sequentially extracted using diethyl ether, chloroform, ethanol, acetone, and distilled water. Preliminary phytochemical screening revealed the presence of carbohydrates, phenols, quinones, flavanones, saponins, tannins, amino acids, and cardiac glycosides, with marked solvent-dependent variation. Quantitative biochemical analysis of the chloroform extract indicated appreciable levels of proteins (40 mg/100 mL), carbohydrates (24 mg/100 mL), and lipids (20 mg/100 mL), highlighting the organic enrichment of termite-modified soils. Thin-layer chromatography further confirmed the presence of monosaccharides (glucose, fructose) and amino acids (tyrosine, tryptophan, proline), reflecting active biochemical turnover within the mound matrix. Antibacterial screening demonstrated moderate inhibitory activity against Bacillus subtilis and Escherichia coli. Notably, larvicidal bioassays against Culex quinquefasciatus revealed significant, dose- and time-dependent mortality, with the chloroform extract exhibiting the highest efficacy across all exposure periods. The findings indicate that termite mound soils harbor extractable semi-polar bioactive metabolites with promising larvicidal potential, underscoring their ecological significance and prospective application in eco-friendly vector control strategies.