Gomes S P, Favero S
Lab de Pesquisa em Entomologia, Univ Anhanguera/Uniderp, Av. Alexandre Herculano, 1400, Jardim Veraneio, 79037-280, Campo Grande, MS, Brasil.
Neotrop Entomol. 2013 Aug;42(4):431-5. doi: 10.1007/s13744-013-0144-2. Epub 2013 Jun 15.
The resistance of triatomines to pyrethroids has been reported in several Latin American countries, including Brazil, indicating the need for the development of new approaches for the control of vectors of the Chagas disease. In here, we evaluated the insecticidal potential of the essential oil of Eucalyptus urograndis (Myrtaceae) against unsexed third and fourth instars of Rhodnius neglectus Lent (Hemiptera: Reduviidae) in topical application, fumigation, surface contact, and repellency . The insecticidal activity of the essential oil tested was detected by topical application (LD50 = 0.1731 μL/insect and LD99 = 0.2948 μL/insect for 24 h), fumigation (LC50 = 0.021 mL/mL air and LC99 = 0.1525 mL/mL air for 24 h) and surface contact (LC50 = 0.7073 μL/cm(2) and LC99 = 4.59 μL/cm(2) for 24 h). Mortality observed after 48-72-h exposure was very high and did not allow for any adjustment of the mortality curve. In the repellency assay, an effect was observed on 80% of tested nymphs. However, no repellency was observed after 24 h of exposure. Eucalyptus urograndis essential oil has a high insecticidal and repellent potential for R. neglectus nymphs, whether serving as a molecular model for new substances or as an alternative for the control of these insects.
在包括巴西在内的几个拉丁美洲国家，已经报道了锥蝽对拟除虫菊酯产生抗性，这表明需要开发控制恰加斯病病媒的新方法。在此，我们评估了巨桉（桃金娘科）精油对未分性别的忽视罗蝽（半翅目：猎蝽科）三龄和四龄若虫在点滴法、熏蒸法、体表接触法和驱避性方面的杀虫潜力。通过点滴法（24小时的半数致死剂量LD50 = 0.1731微升/昆虫，LD99 = 0.2948微升/昆虫）、熏蒸法（24小时的半数致死浓度LC50 = 0.021毫升/毫升空气，LC99 = 0.1525毫升/毫升空气）和体表接触法（24小时的半数致死浓度LC50 = 0.7073微升/平方厘米，LC99 = 4.59微升/平方厘米）检测了所测试精油的杀虫活性。在48 - 72小时暴露后观察到的死亡率非常高，无法对死亡率曲线进行任何调整。在驱避试验中，在80%的受试若虫上观察到了效果。然而，暴露24小时后未观察到驱避作用。巨桉精油对忽视罗蝽若虫具有很高的杀虫和驱避潜力，无论是作为新物质的分子模型还是作为控制这些昆虫的替代物。
