 Corresponding author: Jayapal Subramaniam Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore-641 046, Tamil Nadu, India. Copyright © 2022 Author(s) retain the copyright of this article. This article is published under the terms of the Creative Commons Attribution Liscense 4.0. Bio-efficacy of Karu Nochi, Vitex negundo L. (Lamiaceae) against the dengue vector, Aedes aegypti (L.) Omvir Singh Chechi 1 , Arvind Kumar 1, 2 , Ramasamy Prabhu 3 , Subramanian Manjula 3 , Arokiasamy Reni Prabha 3 , NG Tamil Selvi 4 and Jayapal Subramaniam 5, 6, * 1 Department of Zoology, Research and Development Centre, Bharathiar University, Coimbatore,Tamil Nadu-641046, India. 2 Department of Zoology, Janta Vedic College, Baraut, Baghpat-250611, Uttar Pradesh, India. 3 Department of Zoology, Chikkaiah Naicker College, Erode-638 004, Tamil Nadu, India. 4 Department of Zoology, Government Arts College, C. Mutlur, Chidambaram-608 102, Tamil Nadu, India. 5 Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore-641 046, Tamil Nadu, India. 6 RUSA 2.0-Bharathiar Cancer Theranostics Research Centre (BCTRC), Bharathiar University, Coimbatore-641046, India. GSC Advanced Research and Reviews, 2022, 11(01), 204–209 Publication history: Received on 22 March 2022; revised on 25 April 2022; accepted on 27 April 2022 Article DOI: https://doi.org/10.30574/gscarr.2022.11.1.0114 Abstract 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. Keywords: Vector Control; Biopesticides; Aedes aegypti; Vitex negundo; Larvicidal activity 1. Introduction Mosquitoes have long indeed been a health threat and they could spread diseases to millions of people at risk throughout the worldwide trade and travel. Dengue fever has risen rapidly globally in recent decades. The great majority of dengue cases are asymptomatic or moderate and self-managed, hence the true numbers are underestimated. Misdiagnosed as other febrile illnesses [1], this disease is caused by Dengue Viruses (I, II, III, and IV) and transmitted by Aedes aegypti (Linnaeus, 1762) female mosquito bite. According to WHO, 390 million dengue infections per year are estimated (95 percent credible range 284–528 million), of which 96 million (67–136 million) are clinical (any severity of disease), another research on dengue prevalence predicts 3.9 billion people at risk of infection with DV. Even though there is a risk of infection in 129 countries, 70% of the burden is in Asia [2, 3, 4]. Pesticides have become a daily occurrence and are heavily used to increase crop yields, and repeated use of some synthetic insecticides has caused many harmful issues [5, 6][5]. For example, many pesticide residues found in foods