The Efficiency of Fresh and Commercial Aqueous Extract of Ocimum basilicum Leaves against Culiseta longiareolata Mosquito Larvae

Abstract

Mosquitoes are carriers of diseases that affect both humans and animals. It is crucial to manage their spread during their early developmental stages using natural, environmentally safe materials. This research aimed to assess the effectiveness of Ocimum basilicum leaves-derived aqueous extract (basil plant) as a larvicide against mosquito larvae (Culiseta longiareolata). Third and fourth instar larvae (fifteen larvae per replicate, n = 4) were subjected to varying concentrations of the leaves' aqueous extract (200, 400, 800, and 1600 ppm), with mortality rates recorded after 24 and 48 hours. Both fresh and stored aqueous basil leaf extracts demonstrated efficacy in the eradication of mosquito larvae. The results indicated that the fresh basil leaf extract was more effective than the stored extract, and larval mortality increased proportionally with higher concentrations and longer exposure times. Specifically, after 24 and 48 hours, the mortality rates for the fresh aqueous extract were 36.7% and 66.7%, respectively, compared to 23.3% and 43.3% for the stored extract. Statistically, a significant value was noticed in the fresh extract (p? 0.01). The lethal concentration (LC₉₀) after 48 hours of treatment was determined to be 2425 ppm for the fresh basil leaf extract and 2902 ppm for the stored extract. Furthermore, the LC₅₀ values for the fresh and stored aqueous basil extracts after 24 hours were 1920 ppm and 2361 ppm, respectively. These results suggest that the aqueous extract of basil leaves (O. basilicum) with high concentrations holds potential as a larvicide for controlling Cs. Longiareolata mosquito larvae.