Plagiodera versicolora Laicharting is a highly damaging leaf beetle foraging on willow leaves. In willow germplasm collections, observation has shown that Salix suchowensis Cheng was severely foraged by this leaf beetle while Salix triandra L. was damage free or only slightly damaged. Results of olfactometer bioassays show that the headspace volatiles from leaves of S. triandra significantly repelled adult beetles, suggesting that this species produces volatile repellents against P. versicolora. S. suchowensis had no effect on the beetles. Gas chromatography-mass spectrometry was carried out to profile the headspace volatile organic compounds and 23 compounds from leaves of the alternate species in significantly different concentrations were detected. The effects of 20 chemical analogs on host discrimination were examined. Olfactory response to these chemicals showed that o-cymene, a S. suchowensis specific constituent, significantly attracted adult P. versicolora. In contrast, cis-3-hexenyl acetate, a constituent concentrated more in S. triandra than in S. suchowensis, significantly repelled beetles. Mixing o-cymene and cis-3-hexenyl acetate in comparable concentrations as in the volatiles of S. suchowensis demonstrated that the latter could mask the attracting effect of the former, causing a neutral response by adult beetles to leaves of S. suchowensis against clean air. In addition, chemical analogs have the same effect as plants when resembling volatile organic compounds in real samples. Two volatile metabolites were detected triggering host discrimination by one of the most damaging insect pests to host and non-host willows. The two metabolites are of considerable potential for use as olfactory signs in managing the beetles.

Plagiodera versicolora Laicharting 是一种高度破坏性的叶甲虫，以柳叶为食。在柳树种质资源中，观察表明郑柳被这种叶甲虫严重觅食，而三阳柳无损伤或仅受到轻微损伤。嗅觉计生物测定的结果表明，来自S. triandra叶子的顶空挥发物显着排斥成年甲虫，表明该物种产生针对P. versicolora 的挥发性驱虫剂。苏木对甲虫没有影响。进行了气相色谱 - 质谱分析以分析顶空挥发性有机化合物，并检测到来自替代物种叶子的 23 种化合物，浓度显着不同。检查了 20 种化学类似物对宿主辨别的影响。对这些化学物质的嗅觉反应表明，作为S.suchowensis特定成分的o- cymene显着吸引了成年P. versicolora。相比之下，顺式-3-己烯乙酸酯（一种在S. triandra 中浓度高于S.suchowensis 的成分）显着排斥甲虫。混合邻-伞花烃和顺式与S.suchowensis挥发物中浓度相当的乙酸 -3-己烯酯表明，后者可以掩盖前者的吸引作用，导致成虫对S.suchowensis叶子对清洁空气的中性反应。此外，化学类似物在与真实样品中的挥发性有机化合物相似时具有与植物相同的效果。检测到两种挥发性代谢物，引发了对寄主和非寄主柳树最具破坏性的害虫之一的宿主歧视。这两种代谢物在用作管理甲虫的嗅觉标志方面具有相当大的潜力。