The main objective of the present study was to evaluate under laboratory conditions the toxicity of essential oils (EOs) extracted from Mentha suaveolens L. subsp. timija (Briq.) Harley, Chenopodium ambrosioides L. and Laurus nobilis L. against Varroa destructor adult mites. Also, various combinations were prepared by mixing equal concentrations of any two and all three studied EOs and used to evaluate the combinational acaricidal effects of mixtures against adult Varroa mites. The GC/MS analysis indicated that the main chemical compounds of M. suaveolens subsp. timija EO were menthone (40.42%) and pulegone (19.22%), whereas C. ambrosioides EO is rich in α-terpinene (34.08%), isoascaridol (13.6%), p-cymene (10.95%), thymol (10.26%), ascaridole (10.25%) and carvacrol (7.75%). L. nobilis EO is mainly composed with 1,8-cineol (37.5%) and linalool (14.09%). The fumigation bioassays showed that the three tested EOs showed varroacidal toxicity, whereas no mortality has been observed on honey bees that were exposed to their higher concentrations. The highest acaricidal potency was observed with M. suaveolens subsp. timija (LD₅₀ = 3.360 µl/L_air and LD₉₀ = 7.300 µl/L_air). According to the combination index (CI) calculated by CompuSyn software, the ternary blend combination exhibited high synergistic effectiveness with a CI value of 0.343. All combinations have shown favorable dose reduction with DRI indexes greater than one. Our findings suggest that EO combinations tested could present a promising solution to reduce the effective doses of EOs and constitute a promising alternative to synthetic acaricides.

本研究的主要目的是在实验室条件下评估从Mentha suaveolens L. subsp 中提取的精油 (EO) 的毒性。timija (Briq.) Harley、Chenopodium ambrosioides L. 和Laurus nobilis L. 对抗Varroa destructor成虫。此外，通过将任何两种和所有三种研究过的 EO 混合等浓度来制备各种组合，并用于评估混合物对成年瓦螨的组合杀螨效果。GC/MS 分析表明M. suaveolens subsp.的主要化合物。timija EO 是薄荷酮 (40.42%) 和胡薄荷酮 (19.22%)，而C. ambrosioidesEO 富含 α-萜品烯 (34.08%)、异蕈蕈醇 (13.6%)、对甲基伞花烃 (10.95%)、百里酚 (10.26%)、蛔虫 (10.25%) 和香芹酚 (7.75%)。L. nobilis EO 主要由 1,8-桉树脑 (37.5%) 和芳樟醇 (14.09%) 组成。熏蒸生物测定表明，三种测试的 EO 显示出变异毒性，而在暴露于较高浓度的蜜蜂上没有观察到死亡。M. suaveolens subsp.观察到最高的杀螨能力。timija（LD ₅₀ = 3.360 µl/L_空气和 LD ₉₀ = 7.300 µl/L_空气）。根据 CompuSyn 软件计算的组合指数（CI），三元混合组合表现出较高的协同效应，CI 值为 0.343。所有组合都显示出有利的剂量减少，DRI 指数大于 1。我们的研究结果表明，经测试的 EO 组合可以提供一种有前景的解决方案，以减少 EO 的有效剂量，并构成合成杀螨剂的有前途的替代品。