The Aedes aegypti mosquito is the main vector of arboviruses in Brazil, such as dengue, zika and chikungunya. The use of chemical insecticides is the main control strategy, but resistance is a challenge that stimulates the search for low-toxicity bioactive substances. Plant species native to the Caatinga and Cerrado have high potential for exploitation. Furthermore, the resistance of mosquito vectors to chemical insecticides is not only a matter of concern in Brazil, but also a global challenge. As mobility and climate change continue to impact the spread of arboviruses, the development of sustainable and innovative control methods is becoming increasingly urgent. The aim of this study was to investigate the activity of Lippia gracilis’ essential oil (EO) on adult Ae. aegypti mosquitoes, evaluating possible mechanisms involved in its insecticidal and repellent activity. The methodology used mosquitoes obtained from the colony of the Laboratory of Biotechnology Applied to Parasites and Vectors (LaPaVet). For tarsal and body contact insecticidal activity, groups of adults (n=10) were used in duplicate and exposed to different concentrations of the EO (100 - 350 ppm). Mortality was assessed after 24 hours of exposure. Repellency was assessed using the Y olfactometer with groups of (n=10) females in quintuplicate, all fasted at a concentration of 100 ppm. GraphPad Prism 8.0 was used for statistical analysis (p<0.05). There was (100%) mortality from tarsal and body contact adulticidal activity at 350 ppm. The EO showed good repellent activity at a concentration of 100 ppm (IRE=0.72). Thus, the EO of L. gracilis has repellent and insecticidal activity in the adult stage of the mosquito, being effective for the three methods of analysis for adult mosquitoes, tarsal contact: where it simulates the contact of the insect with the real environment, body contact: where there is direct contact of the substance with the mosquito, and the Y olfactometer repellency test. The EO is therefore considered promising for controlling the Ae. aegypti vector, and is a good biotechnological application of a regional and easily accessible product. It is important to note that its extraction process has a high yield, which is crucial when it comes to the cost-effectiveness of technological innovations.
Comissão Organizadora
Francisco Mendonça Junior
Pascal Marchand
Teresinha Gonçalves da Silva
Isabelle Orliac-Garnier
Gerd Bruno da Rocha
Comissão Científica
Ricardo Olimpio de Moura
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