Dipartimento di Scienze e Tecnologie Agroambientali-Entomologia, Alma Mater Studiorum Università di Bologna, viale G. Fanin 44, 40127 Bologna, Italy.
J Chem Ecol. 2010 Oct;36(10):1114-21. doi: 10.1007/s10886-010-9851-x. Epub 2010 Aug 31.
Females of the pine sawfly Neodiprion sertifer (Hymenoptera Diprionidae) usually avoid Pinus pinea trees as host plants. In contrast, this sawfly species is highly attracted by P. sylvestris and P. nigra trees. Here, we investigated which pine volatiles might mediate this behavior by in situ sampling experiments and olfactometer laboratory tests. Volatiles emitted from P. pinea, P. sylvestris, and P. nigra foliage were sampled by solid-phase microextraction (SPME). Analysis of these volatiles by coupled gaschromatography/mass spectrometry revealed that the relative amounts of the compounds emitted by the three species were significantly different. A discriminant analysis showed that the amounts of limonene and myrcene significantly contributed to the species-specific volatile patterns. Pinus pinea emitted higher relative amounts of limonene than the other pine species. Pinus sylvestris emitted the highest relative amounts of myrcene. When testing the response of N. sertifer females to these pine terpenoids in an olfactometer bioassay, a low amount of limonene was attractive, while a repellent effect was evident when higher amounts were used. The sawfly females showed no significant olfactory response to myrcene. These data suggest that low relative amounts of limonene have a significant function in attracting N. sertifer females, while high amounts might contribute to avoidance of a tree.
雌性松叶蜂通常避免将松树作为寄主植物。相比之下，这种松叶蜂对欧洲赤松和黑松具有高度吸引力。在这里，我们通过原位采样实验和嗅觉计实验室测试研究了哪些松树挥发物可能介导这种行为。通过固相微萃取（SPME）对来自 P. pinea、P. sylvestris 和 P. nigra 树叶的挥发物进行采样。通过气相色谱/质谱联用分析这些挥发物表明，三种物种发出的化合物的相对数量有显著差异。判别分析表明，柠檬烯和月桂烯的含量对种特异性挥发模式有显著贡献。与其他松树物种相比，P. pinea 释放出更高相对含量的柠檬烯。P. sylvestris 释放出最高相对含量的月桂烯。当在嗅觉计生物测定中测试 N. sertifer 雌性对这些松树萜烯的反应时，低量的柠檬烯具有吸引力，而高量则表现出明显的驱避作用。这种松叶蜂的雌性对月桂烯没有明显的嗅觉反应。这些数据表明，低相对含量的柠檬烯在吸引 N. sertifer 雌性方面具有重要作用，而高含量可能有助于避免一棵树。
