The indiscriminate use of acaricides is a problem worldwide and has increased the selection of acaricide-resistant tick populations. The goal of this study was to evaluate the acaricide effects of two essential oils (from Schinus molle and Bulnesia sarmientoi) using the larval immersion test on three Rhipicephalus tick species. Rhipicephalus evertsi, Rhipicephalus appendiculatus and Rhipicephalus pulchelus ticks collected in Kenya, without history of acaricide exposure, were tested, as well as individuals from two populations of Rhipicephalus microplus (with or without history of acaricide exposure), for comparison. The sample most resistant to the treatments was a population of R. microplus with previous acaricide exposure, whereas the least tolerant sample was a strain of the same species that never had contact with acaricides (Porto Alegre strain). Interestingly, the field tick samples without previous acaricide exposure responded to essential oils with a mortality profile resembling that observed in the acaricide-resistant R. microplus field population, and not the susceptible Porto Alegre strain. The essential oil of B. sarmientoi and its two components tested (guaiol and bulnesol) caused the highest mortality rates in the tested species and are potential molecules for future studies on control methods against these species.

不加区别地使用杀螨剂是世界范围内的一个问题，并且增加了抗杀螨剂蜱种群的选择。本研究的目的是使用幼虫浸泡试验对三种Rhipicephalus蜱种进行幼虫浸泡试验，以评估两种精油（来自Schinus molle和Bulnesia sarmientoi）的杀螨效果。Rhipicephalus evertsi、Rhipicephalus appendiculatus和Rhipicephalus pulchelus在肯尼亚收集的没有杀螨剂接触史的蜱，以及来自两个微型 Rhipicephalus种群的个体进行了测试（有或没有杀螨剂接触史），用于比较。对这些处理最耐受的样本是先前接触过杀螨剂的R. microplus种群，而耐受性最低的样本是从未接触过杀螨剂的同一物种的菌株（阿雷格里港菌株）。有趣的是，之前没有接触过杀螨剂的田间蜱样本对精油的反应与在抗杀螨剂的R. microplus田间种群中观察到的死亡率相似，而不是易感的阿雷格里港菌株。B. sarmientoi的精油 其测试的两种成分（愈创木酚和布尼醇）在测试物种中导致最高的死亡率，并且是未来研究针对这些物种的控制方法的潜在分子。