Data underlying the publication: Intraspecific plant variation and nonhost herbivores affect parasitoid host location behaviour

This data belongs to the paper published in Animal Behaviour, with the title: Intraspecific plant variation and nonhost herbivores affect parasitoid host location behaviour. See the published paper and the readme files for information on methods, techniques and other relevant information.<br>Abstract:Parasitoids need to find their hosts in patchy environments that differ in profitability. To maximize foraging efficiency, parasitoids use volatile information of plants on which their hosts feed. The blend of plant volatiles emitted is affected by genetic variation in plants and by the herbivore species feeding on the plant. How parasitoids deal with variation in plant volatiles induced by host or nonhost herbivores on various plant genotypes in a plant stand is unclear. In a wind tunnel, we examined foraging behaviour of the parasitoid Cotesia glomerata in mixes of white cabbage cultivars with host (Pieris brassicae) and nonhost herbivores (Mamestra brassicae or Delia radicum). We specifically studied the efficiency of parasitoids in locating a host-infested plant when having to pass three other plants that varied in volatile emission by cultivar and herbivore identity. We show that foraging decisions of C. glomerata are affected by the apparency of volatile cues from upwind host-infested plants. We found that parasitoids flew over the first three plants more often when the last plant was a host-infested attractive cultivar and the first three plants were a less attractive cultivar, regardless of the presence of host or nonhost herbivores. Furthermore, parasitoids spent more time on the first three plants if these were infested with host or nonhost larvae, and this effect was stronger when the first three plants were of the attractive cultivar. Our results suggest that parasitoids may more easily locate host herbivores on plant genotypes with more apparent volatile information. However, host location efficiency is affected by the contrast with other plumes of plant volatiles derived from genotypic variation in plants and induction of volatiles by nonhost herbivores. Apparency of information on upwind patches influences patch residence time and patch choice and is an important component of optimal foraging in parasitoids.

本数据集关联发表于《动物行为》（Animal Behaviour）期刊的论文，论文标题为：植物种内变异与非寄主植食性昆虫影响寄生蜂（parasitoid）的寄主定位行为。有关研究方法、实验技术及其他相关信息，请参阅已发表的论文与说明文档。
摘要：寄生蜂需要在收益各异的斑块状环境中搜寻寄主。为最大化觅食效率，寄生蜂会利用寄主取食的植物释放的挥发性信息物质。植物释放的挥发性混合物组成会受到植物自身遗传变异以及取食该植物的植食性昆虫种类的影响。目前学界尚不明确，在植物群落中，寄生蜂如何应对由寄主或非寄主植食性昆虫在不同植物基因型上诱导产生的植物挥发性物质变化。本研究在风洞中开展实验，以菜蛾绒茧蜂（Cotesia glomerata）为对象，探究其在混合种植的不同白花甘蓝品种间的觅食行为，这些甘蓝分别携带寄主植食性昆虫菜粉蝶（Pieris brassicae）以及非寄主植食性昆虫甘蓝夜蛾（Mamestra brassicae）或萝卜地种蝇（Delia radicum）。本研究重点考察了寄生蜂在需途经3株因品种与植食性昆虫种类不同而挥发性物质释放模式存在差异的植株后，定位寄主取食植株的效率。研究结果表明，菜蛾绒茧蜂的觅食决策会受到逆风方向寄主取食植株释放的挥发性信号的显著程度的影响。研究发现，当最后一株为寄主取食的高吸引力品种，而前三株为低吸引力品种时，寄生蜂更易直接飞越前三株植株，且该现象不受寄主或非寄主植食性昆虫存在与否的影响。此外，若前三株植株被寄主或非寄主幼虫取食，寄生蜂会在其上花费更多时间；且当这前三株植株为高吸引力品种时，该效应会更为显著。本研究结果提示，寄生蜂更易在挥发性信息更显著的植物基因型上定位寄主植食性昆虫。但寄主定位效率会受到与其他植物挥发性羽流的对比度的影响，而该对比度源于植物的遗传变异以及非寄主植食性昆虫对挥发性物质的诱导。逆风斑块的信息显著程度会影响寄生蜂的斑块停留时间与斑块选择，这也是寄生蜂最优觅食行为的重要组成部分。