Bio-efficacy of Karu Nochi, Vitex negundo L. (Lamiaceae) against the dengue vector, Aedes aegypti (L.)

The dengue vector, Aedes aegypti (L.) is one of the world's deadliest species and it spreads diseases like Zika, chikungunya, dengue, and yellow fever. In this present investigation, we attempt to evaluate the larvicidal toxicity of different solvent extracts and essential oil of Karunochi, Vitex negundo (L.) on third instar larvae of the dengue vector, A. aegypti. The crude extracts were prepared by using soxhlet apparatus and rotary vacuum evaporator technique. The highest mortality was observed in essential oil and ethanolic extract followed by hexane and acetone extracts, the lethal concentrations LC50 (LC90) values were obtained from noticed, for Vn-EO- 218.46 (517.10), Vn-EE 268.37 (592.56), Vn-HE 309.59 (667.33), and Vn-AE 327.88 (748.47), respectively and nil mortality observed in the control treatment. Karunochi, V. negundo essential oil, and ethanolic extract (Vn-EE) were more efficient against A. aegypti than crude extracts of Vn-AE (acetone) and Vn-HE (hexane). Therefore, from our studies the formulations are promising for a low-cost larvicide without isolating an active ingredient, EO’s were tested. The goal of this study is to promote the use of plant-based larvicides in public health programmes.