Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, AC, Av. Normalistas 800, Col. Colinas de la Normal, 44270, Guadalajara, Jalisco, Mexico.
J Med Entomol. 2011 Jul;48(4):822-7. doi: 10.1603/me10140.
Acaricidal effects of three essential oils extracted from Mexican oregano leaves (Lippia graveolens Kunth), rosemary leaves (Rosmarinus officinalis L.), and garlic bulbs (Allium sativum L.) on 10-d-old Rhipicephalus (Boophilus) microplus (Canestrini) tick larvae were evaluated by using the larval packet test bioassay. Serial dilutions of the three essential oils were tested from a starting concentration of 20 to 1.25%. Results showed that both Mexican oregano and garlic essential oils had very similar activity, producing high mortality (90-100%) in all tested concentrations on 10-d-old R. microplus tick larvae. Rosemary essential oil produced >85% larval mortality at the higher concentrations (10 and 20%), but the effect decreased noticeably to 40% at an oil concentration of 5%, and mortality was absent at 2.5 and 1.25% of the essential oil concentration. Chemical composition of the essential oils was elucidated by gas chromatography-mass spectrometry analyses. Mexican oregano essential oil included thymol (24.59%), carvacrol (24.54%), p-cymene (13.6%), and y-terpinene (7.43%) as its main compounds, whereas rosemary essential oil was rich in a-pinene (31.07%), verbenone (15.26%), and 1,8-cineol (14.2%), and garlic essential oil was rich in diallyl trisulfide (33.57%), diallyl disulfide (30.93%), and methyl allyl trisulfide (11.28%). These results suggest that Mexican oregano and garlic essential oils merit further investigation as components of alternative approaches for R. microplus tick control.
三种精油（墨西哥牛至叶、迷迭香叶和大蒜鳞茎）对 10 日龄 Rhipicephalus（Boophilus）microplus 幼虫的杀蜱效果评价通过幼虫包被试验进行。从起始浓度 20 到 1.25%对三种精油进行了连续稀释测试。结果表明，墨西哥牛至和大蒜精油的活性非常相似，在所有测试浓度下对 10 日龄 R. microplus 幼虫均产生了 90-100%的高死亡率。迷迭香叶精油在较高浓度（10%和 20%）下产生了>85%的幼虫死亡率，但在 5%的油浓度下，效果明显下降至 40%，在 2.5%和 1.25%的精油浓度下则没有死亡率。通过气相色谱-质谱分析阐明了精油的化学成分。墨西哥牛至精油的主要化合物为百里酚（24.59%）、香芹酚（24.54%）、对伞花烃（13.6%）和γ-萜品烯（7.43%），而迷迭香叶精油富含α-蒎烯（31.07%）、马鞭草酮（15.26%）和 1,8-桉叶素（14.2%），大蒜精油富含二烯丙基三硫化物（33.57%）、二烯丙基二硫化物（30.93%）和甲基丙烯基三硫化物（11.28%）。这些结果表明，墨西哥牛至和大蒜精油作为替代 R. microplus 控制方法的成分值得进一步研究。
