LARVICIDAL ACTIVITY OF ETHANOLIC EXTRACT OF PIPER ARBOREUM AUBL. (PIPERALES: PIPERACEAE) LEAVES AGAINST AEDES AEGYPTI LINNAEUS, 1762 (DIPTERA, CULICIDAE)

Resumo

Aedes aegypti is one of the main vectors of human arboviruses, thus is essential to discover new alternative tools for its control. Therefore, this study aimed to evaluate the larvicidal effects of the ethanolic extract of Piper arboreum leaves (EEPA) against Aedes aegypti. The extract was prepared in a 70% ethanol extractive solution and was rota-evaporated to obtain the crude extract. In the larvicide assay the third instar larvae (n = 20) were exposed to varying EEPA concentrations (25–200 µg/mL) for 24 h. The larvae were then transferred to fresh glass cups containing only chlorine-free water to assess the mortality rates over 72 h. In addition, larval morphology was evaluated in the experimental groups to determine alterations. Finally, the toxicity of EEPA was assessed in tests with Artemia salina. Our results showed that the larval mortality ranged from 17–100% in a dose-dependent manner after 72 h. The highest concentrations (150 and 200 µg/mL) were more effective than 25 µg/mL and the negative control group. The lethal concentration capable of killing 50% larvae (LC50) obtained for EEPA was 80.54 µg/mL (95%CI: 60.81–106.7 µg/mL). Morphological analyses revealed damage to the chitin layer of larvae exposed to EEPA, particularly at higher concentrations. The toxicity test of EEPA on A. salina showed an LC50 of 58 µg/mL (95%CI: 45–70.5µg/mL), which indicates elevated toxicity. Therefore, our results demonstrated that EEPA can be used as an alternative for controlling A. aegypti larvae, especially in artificial breeding sites, due to its high toxicity.