Department of Chemistry, Simon Fraser University, 8888 Univ. Dr., Burnaby, BC, V5A 1S6, Canada.
Agriculture and Agri-Food Canada, Beaverlodge Research Farm, P.O. Box 29, Beaverlodge, AB, T0H 0C0, Canada.
Sci Rep. 2023 Jul 11;13(1):11195. doi: 10.1038/s41598-023-38187-6.
The honey bee is responsible for pollination of a large proportion of crop plants, but the health of honey bee populations has been challenged by the parasitic mite Varroa destructor. Mite infestation is the main cause of colony losses during the winter months, which causes significant economic challenges in apiculture. Treatments have been developed to control the spread of varroa. However, many of these treatments are no longer effective due to acaricide resistance. In a search of varroa-active compounds, we tested the effect of dialkoxybenzenes on the mite. A structure-activity relationship revealed that 1-allyloxy-4-propoxybenzene is most active of a series of dialkoxybenzenes tested. We found that three compounds (1-allyloxy-4-propoxybenzene, 1,4-diallyloxybenzene and 1,4-dipropoxybenzene) cause paralysis and death of adult varroa mites, whereas the previously discovered compound, 1,3-diethoxybenzene, which alters host choice of adult mites in certain conditions, did not cause paralysis. Since paralysis can be caused by inhibition of acetylcholinesterase (AChE), a ubiquitous enzyme in the nervous system of animals, we tested dialkoxybenzenes on human, honey bee and varroa AChE. These tests revealed that 1-allyloxy-4-propoxybenzene had no effects on AChE, which leads us to conclude that 1-allyloxy-4-propoxybenzene does not exert its paralytic effect on mites through AChE. In addition to paralysis, the most active compounds affected the ability of the mites to find and remain at the abdomen of host bees provided during assays. A test of 1-allyloxy-4-propoxybenzene in the field, during the autumn of 2019 in two locations, showed that this compound has promise in the treatment of varroa infestations.
蜜蜂是很大一部分作物植物的授粉媒介,但蜜蜂种群的健康受到寄生螨瓦螨的挑战。螨类的侵袭是冬季蜂群损失的主要原因,这给养蜂业带来了重大的经济挑战。已经开发出了一些处理方法来控制瓦螨的传播。然而,由于杀螨剂的抗性,许多这些处理方法已经不再有效。在寻找瓦螨活性化合物的过程中,我们测试了二烷氧基苯对螨虫的影响。构效关系表明,在所测试的一系列二烷氧基苯中,1-丙烯氧基-4-丙氧基苯最具活性。我们发现三种化合物(1-丙烯氧基-4-丙氧基苯、1,4-二丙烯氧基苯和 1,4-二丙氧基苯)会导致成年瓦螨麻痹和死亡,而之前发现的化合物 1,3-二乙氧基苯在某些情况下会改变成年螨虫的宿主选择,但不会导致麻痹。由于麻痹可能是由于乙酰胆碱酯酶(AChE)的抑制引起的,而 AChE 是动物神经系统中普遍存在的酶,我们测试了二烷氧基苯对人、蜜蜂和瓦螨 AChE 的影响。这些测试表明,1-丙烯氧基-4-丙氧基苯对 AChE 没有影响,这使我们得出结论,1-丙烯氧基-4-丙氧基苯不会通过 AChE 对螨虫产生麻痹作用。除了麻痹作用外,最活跃的化合物还影响了螨虫在试验中找到并留在宿主蜜蜂腹部的能力。2019 年秋季在两个地点进行的 1-丙烯氧基-4-丙氧基苯田间试验表明,该化合物在治疗瓦螨感染方面具有潜力。