Fundação Oswaldo Cruz - FIOCRUZ, Instituto Oswaldo Cruz - IOC, Programa de Pós-graduação em Biodiversidade e Saúde, Rio de Janeiro, RJ, Brasil.
Fundação Oswaldo Cruz - FIOCRUZ, Instituto Oswaldo Cruz - IOC, Laboratório Integrado: Simulídeos e Oncocercose & Entomologia Médica e Forense, Rio de Janeiro, RJ, Brasil.
Braz J Biol. 2024 Oct 28;84:e283724. doi: 10.1590/1519-6984.283724. eCollection 2024.
The use of botanical insecticides has increased in recent years due to the demand for effective products, particularly against insects resistant to conventional insecticides. Among these is Aedes aegypti, a well-adapted mosquito to urban environments that opportunistically feeds on humans and animals, contributing to the spread of virus. We evaluated the potential of essential oils (EOs) extracted from Eucalyptus citriodora, Eucalyptus staigeriana, Eucalyptus caryophyllus, and Mentha arvensis in terms of their larvicidal activity against Ae. aegypti. EOs' compounds were determined using gas chromatography-mass spectrometry (GC-MS). Bioassays were performed on third instar larvae of Ae. aegypti to evaluate the larvicidal effects of EO dilutions in dimethyl sulfoxide (DMSO) at different concentrations. Mortality rates were observed over a 72-hour period to determine the efficacy of the treatments. Citronellal (86.64) predominated in E. citriodora, limonene in E. staigeriana (41.68), eugenol in E. caryophyllus (87.76), and menthol in M. arvensis (51.53%). EOs exhibited larvicidal activity from 10 ppm, with notable efficacy at 85 ppm, in which those from E. staigeriana and M. arvensis caused maximum mortality to Ae. aegypti larvae. Results revealed distinct efficacy patterns among EOs, with E. staigeriana displaying high toxicity within 24 h, achieving LC50 and LC95 values of 47.04 ppm and 97.35 ppm, respectively. Larvicidal effects within 1 h were observed for E. citriodora and E. caryophyllus. This study underscores larvicidal efficacy against Ae. aegypti, notably E. staigeriana, which had the lowest LC50 value. The findings indicate that the tested samples have potential for use as bioinsecticides.
近年来，由于对有效产品的需求增加，特别是针对对传统杀虫剂具有抗性的昆虫，植物性杀虫剂的使用有所增加。其中包括埃及伊蚊，这是一种适应城市环境的蚊子，它会伺机吸食人类和动物的血液，从而传播病毒。我们评估了从柠檬桉（Eucalyptus citriodora）、斯泰吉亚桉（Eucalyptus staigeriana）、蓝桉（Eucalyptus caryophyllus）和野薄荷（Mentha arvensis）中提取的精油（EOs）在针对埃及伊蚊的幼虫杀灭活性方面的潜力。使用气相色谱-质谱联用仪（GC-MS）测定了 EOs 的化合物。在 DMSO 中的不同浓度下，对埃及伊蚊的三龄幼虫进行了生物测定，以评估 EO 稀释液的幼虫杀灭效果。在 72 小时内观察死亡率以确定处理效果。柠檬醛（86.64）在柠檬桉中占优势，柠檬烯在斯泰吉亚桉中占优势（41.68），丁香酚在蓝桉中占优势（87.76），薄荷醇在野薄荷中占优势（51.53%）。EOs 从 10 ppm 开始表现出幼虫杀灭活性，在 85 ppm 时效果显著，其中斯泰吉亚桉和野薄荷精油对埃及伊蚊幼虫的致死率最高。结果表明，EOs 之间存在明显的功效模式，斯泰吉亚桉在 24 小时内表现出高毒性，达到 LC50 和 LC95 值分别为 47.04 ppm 和 97.35 ppm。在 1 小时内观察到柠檬桉和蓝桉的幼虫杀灭效果。本研究强调了针对埃及伊蚊的幼虫杀灭功效，特别是斯泰吉亚桉，其 LC50 值最低。研究结果表明，测试样品具有作为生物杀虫剂使用的潜力。
