Larvicidal effects of Myrciaria floribunda (H. West ex Willd.) O. Berg nanoemulsion against Aedes aegypti (Linnaeus, 1762)

Dengue remains a major health problem among the arboviruses transmitted by the Aedes aegypti (Diptera: Culicidae). From December 2023 until November 2024, 14 million dengue cases were reported in 80 countries. The use of synthetic insecticides is the classical method to interrupt the transmission of arboviruses. However, the widespread use induced Ae. aegypti to develop biological resistance mechanisms. In addition, they are often toxic to the environment and humans. Therefore, this work aimed to evaluate the insecticidal properties of the Myrciaria floribunda essential oil as an eco-friendly nanoemulsion in third-instar larvae. The main constituents of the essential oil were 1,8-cineole (13.03 %), ( E )-nerolidol (13.48 %), and β-selinene (12.13 %). The nanoemulsion showed a proper appearance with a bluish reflection. Its droplet size diameter was 88.34 ± 0.946 nm, the polydispersity index was 0.276 ± 0.014, and the zeta potential was −34.70 ± 1.311 mV. Furthermore, the nanoemulsion also showed stability after 15 days of preparation and when exposed to increasing temperatures. Concerning the larvicidal effect, the nanoemulsion exhibited LC 50 values of 233.65 (199.9–272.5) µg/mL after 48 h of exposure. Molecular docking studies suggest that the sesquiterpenes ( E )-nerolidol, β-selinene, and α-selinene may be associated with insecticidal activity due to their interactions with the enzyme Aa AChE1. Therefore, this study described the Myrciaria floribunda essential oil nanoemulsion, obtained from green methods, as a practical vector control for Aedes aegypti larvae. • Myrciaria floribunda essential oil showed 1,8-cineole, ( E )-nerolidol, and β-selinene as major compounds. • The M. floribunda nanoemulsion was stable and exhibited significant larvicidal activity against Aedes aegypti . • Molecular docking suggests that sesquiterpenes such as ( E )-nerolidol and β-selinene interact with the AaAChE1 enzyme. • This is the first report on the larvicidal properties of essential oil against Aedes aegypti of the Myrciaria genus.