Larvicidal activity of aqueous extract and hydrolate of Melosa leaves against Aedes aegypti

• Autor(a) principal: Souza, Elizângela Maria de
• Data de Publicação: 2024
• Outros Autores: Pereira, Emanuela Beatriz Souza Silva, Lorenzo, Vitor Prates, Costa, Eliatânia Clementino, Amaral, Daniel Ferreira, Moreira, Marília Victória de Souza, Oliveira, Enzo Loandos
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Revista Ouricuri (Online)
• Texto Completo: https://www.revistas.uneb.br/index.php/ouricuri/article/view/18890
• topic: Arboviroses; Caatinga; Ruellia asperula.; Arboviruses; Caatinga; Phytolarvicida; Ruellia asperula

The insect Aedes aegypti is the vector of the virus that causes arboviruses such as Dengue, Urban Yellow Fever, Zika and Chikungunya. Currently, the fight and control of this mosquito occurs through larvicides and synthetic larvicide, elimination of breeding sites and awareness campaigns. Therefore, it is necessary to study low-cost alternative methods that do not harm the environment, such as botanical insecticides. In this scenario, the Caatinga has many important species for prospecting insecticidal and larvicidal molecules.The present work aimed to evaluate in vitro the larvicidal effect of the aqueous extract and hydrolate of Ruellia asperula against the larvae of the A. aegypti mosquito. The experimental tests were carried out in the Chemistry Laboratory of the Petrolina Zona Rural Campus. Two bioassays were carried out to obtain the results: one to evaluate the effect of the aqueous extract (dry leaves) and another to evaluate the effect of the hydrolate (fresh leaves) on the larval stage (L2/L3) of A. aegypti, with a completely randomized design, seven treatments (0.1, 2, 3, 4, 5 and 6% of the extract) in triplicate; and five treatments (0, 12.5, 25, 50 and 100% of the hydrolate) in triplicate. The larval mortality rate was analyzed in 24h, 48h and 72h. Each sampling unit consisted of a glass beaker (50 mL) with ten larvae, totaling thirty larvae per treatment. The bioassays revealed larvicidal potential, the aqueous honey extract after 24 hours of exposure caused mortality of 96, 67% (T4) and 100% (T6 and T7) of the larvae. Melosa hydrolate with a concentration of 100% hydrolate led to 100% mortality of larvae within 24 hours. The findings of this study revealed that the aqueous extract and hydrolate of R. asperula are promising natural larvicides and can help control A, aegypti. However, more research involving analysis of the chemical composition, toxicity and cytotoxicity, and economic viability of these products are necessary.