在植物中诱导反应,由食草动物发起,在食草动物之间创造性状介导的间接相互作用的潜力。对初始食草动物的反应可能会改变许多植物性状,随后会改变其他食草动物的生态过程。虽然普通,分类学上遥远的食草动物之间的间接相互作用,比如哺乳动物和昆虫,在分类学相关物种之间的研究较少(即,昆虫-昆虫)。就哺乳动物与昆虫的相互作用而言,对昆虫数量的影响(例如,密度)得到了相对较好的研究,而对性能的影响(例如,繁殖力)很少被探索。此外,很少有研究探索针叶植物上的哺乳动物-昆虫相互作用。这项研究的目的是研究哺乳动物诱导的反应对昆虫性能的影响。我们专门研究了驼鹿(Alcesalces)浏览对苏格兰松树(Pinussylvestris)的影响以及随后对锯蝇(Neodiprionsertifer)性能的影响。锯蝇幼虫被饲养在浏览上,剪裁,在受控田间试验中,未浏览对照松树。之后,测量茧重量。响应于浏览测量针C:N比和二萜含量。在驼鹿浏览的树木上,锯蝇的性能得到了提高。与未浏览的树木相比,浏览和修剪的树木的茧重量(繁殖力的代表)分别高出9%和13%。茧的重量与针C:N的比例弱相关,与未浏览的树木相比,浏览的树木的C:N比率较低。针二萜含量,已知会影响锯蝇的性能,既不受浏览处理的影响,也不与锯蝇体重相关。我们得出结论,哺乳动物食草动物可以影响昆虫食草动物的性能,对生态群落有潜在影响,对昆虫种群动态特别重要。测得的植物变量不能完全解释对锯蝇性能的影响,为考虑哺乳动物浏览影响昆虫性能而引起的其他植物反应提供了起点。
Induced responses in plants, initiated by herbivory, create potential for trait-mediated indirect interactions among herbivores. Responses to an initial herbivore may change a number of plant traits that subsequently alter ecological processes with additional herbivores. Although common, indirect interactions between taxonomically distant herbivores, such as mammals and insects, are less studied than between taxonomically related species (i.e., insect-insect). In terms of mammal-insect interactions, effects on insect numbers (e.g., density) are relatively well studied, whereas effects on performance (e.g., fecundity) are rarely explored. Moreover, few studies have explored mammal-insect interactions on coniferous plants.The aim of this study was to investigate the effect of mammalian induced responses on insect performance. We specifically investigated the effect of moose (Alces alces) browsing on Scots pine (Pinus sylvestris) and subsequent effects on sawfly (Neodiprion sertifer) performance.Sawfly larvae were reared on browsed, clipped, and unbrowsed control pine trees in a controlled field experiment. Afterward, cocoon weight was measured. Needle C:N ratio and di-terpene content were measured in response to browsing.Sawfly performance was enhanced on trees browsed by moose. Cocoon weight (proxy for fecundity) was 9 and 13% higher on browsed and clipped trees compared to unbrowsed trees. Cocoon weight was weakly related to needle C:N ratio, and browsed trees had lower a C:N ratio compared to unbrowsed trees. Needle di-terpene content, known to affect sawfly performance, was neither affected by the browsing treatments nor did it correlate with sawfly weight.We conclude that mammalian herbivory can affect insect herbivore performance, with potential consequences for ecological communities and with particular importance for insect population dynamics. The measured plant variables could not fully explain the effect on sawfly performance providing a starting point for the consideration of additional plant responses induced by mammalian browsing affecting insect performance.