Abstract The leaf beetle Diorhabda carinulata Desbrochers (Coleoptera: Chrysomelidae) was introduced into the United States in 1999 for classical biological control of the exotic woody invader saltcedar (Tamarix spp. L. [Caryophyllales: Tamaricaceae]). The recent southern expansion of the range of D. carinulata in the United States has precipitated conflict between proponents of biological control of Tamarix and those with concerns over habitat conservation for avian species. Several semiochemicals that mediate aggregations by this species have been reported, but no repellent compounds have been recorded thus far. We now report a repellent compound, 4-oxo-(E)-2-hexenal, induced by adult D. carinulata feeding on saltcedar foliage. Collection of headspace volatiles, gas chromatography mass spectrometry, and electroantennographic analyses identified 4-oxo-(E)-2-hexenal as an insect-induced compound that is antennally active. Behavioral and exposure assays were conducted to test for repellency and toxicity in adults and larvae. Headspace volatiles were also collected from adult males exposed to 4-oxo-(E)-2-hexenal to determine the impact exposure might have on the emission of the aggregation pheromone. 4-Oxo-(E)-2-hexenal elicited electrophysiological responses in adults of both sexes. Behavioral responses indicated repellency across multiple doses for reproductive D. carinulata adults but not in nonreproductive adults. Exposure assays indicated altered behaviors in first instar larvae and adults, but not in third instar larvae. Collection of headspace volatiles indicated that exposure to 4-oxo-(E)-2-hexenal did not alter emission of the D. carinulata aggregation pheromone by adult males. The continued development and field deployment of this repellent compound may provide a new tool for the management of D. carinulata.

中文翻译：

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从盐雪松（柽柳属）挥发的草食动物诱导植物对 Diorhabda carinulata（鞘翅目：Chrysomelidae）有排斥作用

摘要 叶甲虫 Diorhabda carinulata Desbrochers (Coleoptera: Chrysomelidae) 于 1999 年被引入美国，用于对外来木质入侵者盐雪松 (Tamarix spp. L. [Caryophyllales: Tamaricaceae]) 进行经典生物防治。最近在美国南部的 D. carinulata 范围的扩展引发了柽柳生物控制的支持者和那些担心鸟类栖息地保护的人之间的冲突。已经报道了几种介导该物种聚集的化学信息素，但迄今为止尚未记录到驱虫化合物。我们现在报告了一种驱虫剂化合物 4-oxo-(E)-2-hexenal，由成年 D. carinulata 以盐雪松树叶为食。顶空挥发物的收集，气相色谱质谱，触角电图分析确定 4-oxo-(E)-2-hexenal 是一种昆虫诱导化合物，具有触角活性。进行行为和暴露试验以测试成虫和幼虫的排斥性和毒性。还从暴露于 4-oxo-(E)-2-hexenal 的成年男性中收集顶空挥发物，以确定暴露可能对聚集信息素的排放产生的影响。4-Oxo-(E)-2-hexenal 引起男女成人的电生理反应。行为反应表明，对繁殖性 D. carinulata 成虫在多次剂量下具有排斥性，但在非生殖性成虫中则不然。暴露试验表明一龄幼虫和成虫的行为改变，但三龄幼虫没有。顶空挥发物的收集表明，暴露于 4-oxo-(E)-2-hexenal 不会改变 D. 成年男性的carinulata聚集信息素。这种驱虫剂化合物的持续开发和现场部署可能会为 D. carinulata 的管理提供一种新工具。