Department of Entomology, University of Wisconsin-Madison, Madison, WI, USA.
Department of Entomology, Iowa State University, Ames, IA, USA.
J Med Entomol. 2022 Sep 14;59(5):1694-1699. doi: 10.1093/jme/tjac111.
Three compounds synthetically-derived from botanicals sources, ethyl perillyl carbonate, geranyl isovalerate, and citronellyl cyclobutane carboxylate, were tested for repellent activity against Ixodes scapularis Say in a field trial. Tick drags were treated with the compounds or with N, N-diethyl-m-toluamide (DEET) at high (0.25 mg/cm2) or low (0.16 mg/cm2) concentrations. Negative controls included untreated drags and drags treated with acetone, the carrier for all repellents. Freshly treated drags (within 20 min) were used to collect I. scapularis ticks at a county park in Wisconsin. To assess effectiveness, we measured tick encounter rates, detachment rate, and time to detachment. None of the repellent treatments, including DEET, resulted in significantly fewer encounters compared to both control treatments. However, the percentage of ticks that detached within 3 min was significantly higher on drags treated with repellents compared to controls. DEET was the most effective, repelling 69.7-87% of ticks by 3 min, but the effectiveness of the three test compounds was still high, with 42-87% of ticks detaching by 3 min. For time to detachment, there were no significant differences between DEET and the three test compounds. We conclude that these synthetically-derived repellents were effective against I. scapularis in a field trial and could be viable alternatives to DEET.
三种从植物源合成的化合物，即乙基胡椒基碳酸酯、香叶基异戊酸酯和香茅基环丁烷羧酸酯，在野外试验中被测试了对肩突硬蜱的驱避活性。蜱虫拖曳物用这些化合物或 N，N-二乙基间甲苯酰胺（DEET）以高（0.25 mg/cm2）或低（0.16 mg/cm2）浓度处理。阴性对照包括未处理的拖曳物和用丙酮处理的拖曳物，丙酮是所有驱避剂的载体。新鲜处理的拖曳物（在 20 分钟内）用于在威斯康星州的一个县公园收集肩突硬蜱。为了评估效果，我们测量了蜱虫的遭遇率、脱落率和脱落时间。与两种对照处理相比，包括 DEET 在内的任何驱避剂处理都没有导致遭遇率显著降低。然而，与对照相比，在处理过驱避剂的拖曳物上，在 3 分钟内脱落的蜱虫百分比显著更高。DEET 是最有效的，在 3 分钟内驱避了 69.7-87%的蜱虫，但三种测试化合物的效果仍然很高，在 3 分钟内有 42-87%的蜱虫脱落。对于脱落时间，DEET 和三种测试化合物之间没有显著差异。我们得出结论，这些合成的驱避剂在野外试验中对肩突硬蜱有效，并且可以替代 DEET。
