Kerr Jessica L, Kelly Dave, Bader Martin K-F, Brockerhoff Eckehard G
Scion (New Zealand Forest Research Institute), Christchurch, New Zealand.
University of Canterbury, School of Biological Sciences, Centre for Integrative Ecology, Christchurch, New Zealand.
J Chem Ecol. 2017 Jan;43(1):17-25. doi: 10.1007/s10886-016-0792-x. Epub 2016 Nov 10.
Plant-feeding insects use visual and olfactory cues (shape, color, plant volatiles) for host location, but the relative importance of different cues and interactions with non-host-plant volatiles in ecosystems of varying plant biodiversity is unclear for most species. We studied invasive bark beetles and wood borers associated with pine trees to characterize interactions among color, host and non-host volatiles, by employing traps that mimic tree trunks. Cross-vane flight intercept traps (black, green, red, white, yellow, clear) and black funnel traps were used with and without attractants (α-pinene + ethanol), repellents (non-host green leaf volatiles, 'GLV'), and attractant/repellent combinations in four pine forests in New Zealand. We trapped 274,594 Hylurgus ligniperda, 7842 Hylastes ater, and 16,301 Arhopalus ferus. Trap color, attractant, and color × attractant effects were highly significant. Overall, black and red traps had the highest catches, irrespective of the presence of attractants. Alpha-pinene plus ethanol increased trap catch of H. ligniperda 200-fold but only 6-fold for H. ater and 2-fold for A. ferus. Green leaf volatiles had a substantial repellent effect on trap catch of H. ligniperda but less on H. ater and A. ferus. Attack by H. ligniperda was halved when logs were treated with GLV, and a similar effect was observed when logs were placed among broadleaved understory shrubs emitting GLV. Overall, H. ligniperda was most strongly affected by the olfactory cues used, whereas H. ater and A. ferus were more strongly affected by visual cues. Collectively, the results support the semiochemical diversity hypothesis, indicating that non-host plant volatiles from diverse plant communities or artificial dispensers can contribute to resistance against herbivores by partly disrupting host location.
以植物为食的昆虫利用视觉和嗅觉线索（形状、颜色、植物挥发物）来寻找宿主，但对于大多数物种而言，在植物生物多样性各异的生态系统中，不同线索的相对重要性以及与非宿主植物挥发物的相互作用尚不清楚。我们研究了与松树相关的入侵性树皮甲虫和蛀木虫，通过使用模仿树干的诱捕器来表征颜色、宿主和非宿主挥发物之间的相互作用。在新西兰的四个松树林中，使用了带有和不带有引诱剂（α-蒎烯+乙醇）、驱避剂（非宿主绿叶挥发物，“GLV”）以及引诱剂/驱避剂组合的交叉叶片飞行拦截诱捕器（黑色、绿色、红色、白色、黄色、透明）和黑色漏斗诱捕器。我们捕获了274594只木小蠹、7842只暗杉小蠹和16301只锈色粒肩天牛。诱捕器颜色、引诱剂以及颜色×引诱剂的效应非常显著。总体而言，无论是否存在引诱剂，黑色和红色诱捕器的捕获量最高。α-蒎烯加乙醇使木小蠹的诱捕量增加了200倍，但对暗杉小蠹仅增加了6倍，对锈色粒肩天牛仅增加了2倍。绿叶挥发物对木小蠹的诱捕量有显著的驱避作用，但对暗杉小蠹和锈色粒肩天牛的作用较小。当原木用GLV处理时，木小蠹的侵害减半，当原木放置在散发GLV的阔叶林下灌木中时也观察到了类似的效果。总体而言，木小蠹受所用嗅觉线索的影响最大，而暗杉小蠹和锈色粒肩天牛受视觉线索的影响更大。总的来说，这些结果支持了化学生态多样性假说，表明来自不同植物群落或人工分配器中的非宿主植物挥发物可以通过部分扰乱宿主定位来增强对食草动物的抗性。
