Species-specific plant-mediated effects between herbivores converge at high damage intensity.
Species-specific plant-mediated effects between herbivores converge at high damage intensity.
复制标题
食草动物之间的物种特异性植物介导的作用以高损伤强度融合。
作者：
植物经常暴露在多种食草动物的侵袭下，这些捕食者的密度(或相应的危害强度)在田间往往波动很大。植物介导的相互作用在不同的草食物种和不同的取食强度下是不同的，但关于草食动物的身份和密度是如何相互作用来决定植物反应和草食动物适合度的知之甚少。在这里，我们使用Triadica sebifera(牛脂)和两种常见的和丰富的专业昆虫草食动物Bikasha collaris(跳甲)和Heterapoderopsis biallosicollis(象鼻虫)来研究这个问题。通过控制这两种食草动物的食叶成虫的密度，我们测试了跳甲或象甲成虫引起的叶片伤害强度的变化如何影响食根跳甲幼虫的行为，并评估了诱导的牛脂根部性状预测跳甲幼虫行为的可能性。我们发现，象甲成虫随着叶片伤害强度的增加，幼虫的存活率持续下降。相反，同种跳甲成虫在低危害时提高了幼虫的存活率，在高危害时降低了幼虫的存活率，导致单峰模式。化学分析表明，随着象甲成虫叶片危害程度的增加，根部碳水化合物含量呈线性下降，根单宁含量呈线性增加，而象甲成虫在低危害时的作用与象甲成虫相反，而在高危害时与象甲成虫的作用相似。此外，在所有摄食处理中，跳甲幼虫的存活率与碳水化合物浓度呈正相关，与单宁浓度呈负相关，这表明根的初级和次生代谢可能是观察到的对跳甲幼虫的影响的基础。我们的研究表明，食草动物的身份和密度相互作用，决定了系统的植物反应和植物对食草动物的影响。特别是，影响在低密度下是物种特有的，但在高密度下会聚在一起。这些发现强调了在研究草食动物之间由植物介导的相互作用的驱动因素时同时考虑草食动物的身份和密度的重要性，这促进了我们对草食动物群落和陆地食物网的结构和组成的理解。
Plants are often exposed to multiple herbivores and densities of these attackers (or corresponding damage intensities) often fluctuate greatly in the field. Plant‐mediated interactions vary among herbivore species and with changing feeding intensity, but little is known about how herbivore identity and density interact to determine plant responses and herbivore fitness. Here, we investigated this question using Triadica sebifera (tallow) and two common and abundant specialist insect herbivores, Bikasha collaris (flea beetle) and Heterapoderopsis bicallosicollis (weevil). By manipulating densities of leaf‐feeding adults of these two herbivore species, we tested how variations in the intensity of leaf damage caused by flea beetle or weevil adults affected the performance of root‐feeding flea beetle larvae and evaluated the potential of induced tallow root traits to predict flea beetle larval performance. We found that weevil adults consistently decreased the survival of flea beetle larvae with increasing leaf damage intensities. In contrast, conspecific flea beetle adults increased their larval survival at low damage then decreased larval survival at high damage, resulting in a unimodal pattern. Chemical analyses showed that increasing leaf damage from weevil adults linearly decreased root carbohydrates and increased root tannin, whereas flea beetle adults had opposite effects as weevil adults at low damage and similar effects as them at high damage. Furthermore, across all feeding treatments, flea beetle larval survival correlated positively with concentrations of carbohydrates and negatively with concentration of tannin, suggesting that root primary and secondary metabolism might underlie the observed effects on flea beetle larvae. Our study demonstrates that herbivore identity and density interact to determine systemic plant responses and plant‐mediated effects on herbivores. In particular, effects are species‐specific at low densities, but converge at high densities. These findings emphasize the importance of considering herbivore identity and density simultaneously when investigating factors driving plant‐mediated interactions between herbivores, which advances our understanding of the structure and composition of herbivore communities and terrestrial food webs.
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影响因子：
5.6
作者：
Eisenring, Michael;Meissle, Michael;Romeis, Jorg
通讯作者：
Romeis, Jorg
影响因子：
3.4
作者：
Erwin, Alexis C.;Geber, Monica A.;Agrawal, Anurag A.
通讯作者：
Agrawal, Anurag A.
影响因子：
1.9
作者：
Agrawal, AA;Karban, R
通讯作者：
Karban, R
影响因子：
3.7
作者：
Heil M;Ibarra-Laclette E;Adame-Álvarez RM;Martínez O;Ramirez-Chávez E;Molina-Torres J;Herrera-Estrella L
通讯作者：
Herrera-Estrella L
影响因子：
3.4
作者：
Agrawal, AA
通讯作者：
Agrawal, AA