The walnut twig beetle, Pityophthorus juglandis Blackman, and its associated fungal pathogen that causes thousand cankers disease, currently threaten the viability of walnut trees across much of North America. During a 2011 assessment of seasonal flight patterns of P. juglandis with yellow sticky traps baited with the male-produced aggregation pheromone component, 3-methyl-2-buten-1-ol, dramatically reduced catches were recorded when Tree Tanglefoot adhesive was used to coat the traps. In summer 2011, two trap adhesives were tested for potential repellency against P. juglandis in a field trapping bioassay. SuperQ extracts of volatiles from the most repellent adhesive were analyzed by gas chromatography-mass spectrometry, and limonene and α-pinene were identified as predominant components. In field-based, trapping experiments both enantiomers of limonene at a release rate of ~700 mg/d conferred 91-99% reduction in trap catches of P. juglandis to pheromone-baited traps. (+)- and (‒)-α-Pinene reduced trap catch by 40 and 53%, respectively, at the highest release rate tested. While a combination of R-(+)-limonene and (+)-α-pinene resulted in a 97% reduction in the number of P. juglandis caught, the combination did not consistently result in greater flight trap catch reduction than individual limonene enantiomers. The repellent effect of limonene may be valuable in the development of a semiochemical-based tool for management of P. juglandis and thousand cankers disease.

中文翻译：

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诱捕失败导致发现有效的核桃枝甲虫化学驱虫剂

核桃枝甲虫 Pityophthorus juglandis Blackman 及其相关的导致千口疮的真菌病原体目前威胁着北美大部分地区核桃树的生存能力。在 2011 年对 P. juglandis 季节性飞行模式的评估中，黄色粘性陷阱以雄性产生的聚集信息素成分 3-methyl-2-buten-1-ol 为诱饵，当使用 Tree Tanglefoot 粘合剂时记录到的捕获量显着减少覆盖陷阱。2011 年夏天，在田间诱捕生物测定中测试了两种诱捕粘合剂对胡桃木的潜在排斥性。使用气相色谱-质谱法分析了来自最防水粘合剂的 SuperQ 挥发物提取物，并确定了柠檬烯和 α-蒎烯为主要成分。在实地，诱捕实验中，两种柠檬烯的对映异构体在 ~700 毫克/天的释放速率下都使胡麻的诱捕器捕获量减少了 91-99%，而以信息素为诱饵的诱捕器。(+)- 和 (‒)-α-Pinene 在测试的最高释放率下分别减少了 40% 和 53% 的陷阱捕获量。虽然 R-(+)-柠檬烯和 (+)-α-蒎烯的组合使捕获的胡桃数量减少了 97%，但与单个柠檬烯对映异构体相比，该组合并没有始终如一地导致更大的飞行陷阱捕获减少. 柠檬烯的驱避作用在开发基于信息化学的工具来管理胡桃和千口疮病方面可能很有价值。分别以测试的最高释放速率。虽然 R-(+)-柠檬烯和 (+)-α-蒎烯的组合使捕获的胡桃数量减少了 97%，但与单个柠檬烯对映异构体相比，该组合并没有始终如一地导致更大的飞行陷阱捕获减少. 柠檬烯的驱避作用在开发基于信息化学的工具来管理胡桃和千口疮病方面可能很有价值。分别以测试的最高释放速率。虽然 R-(+)-柠檬烯和 (+)-α-蒎烯的组合使捕获的胡桃数量减少了 97%，但与单个柠檬烯对映异构体相比，该组合并没有始终如一地导致更大的飞行陷阱捕获减少. 柠檬烯的驱避作用在开发基于信息化学的工具来管理胡桃和千口疮病方面可能很有价值。