Herbivore-induced volatile blends with both “fast” and “slow” components provide robust indirect defense in nature

1.Plants emit volatile blends specific to particular herbivore interactions, which predators and parasitoids learn to associate with prey, increasing herbivore mortality and thereby plant fitness in a phenomenon termed indirect defense.

2.Herbivore-induced plant volatile blends commonly include both rapid, transient green leaf volatiles (GLVs) and delayed, enduring sesquiterpenes. A few laboratory studies indicate that insects can use plant volatiles to time behavior, but it is not known whether and how the temporal dynamics of plant volatile blends influence their function in indirect defense.

3.We characterized the activity of the native herbivores Manduca sexta and Tupiocoris notatus and their predators, Geocoris spp., on their host plant Nicotiana attenuata in their natural habitat. Diurnal predator activity only partially overlapped with variable herbivore activity, and herbivore attack at the beginning or end of the photophase elicited plant volatile blends with distinct GLV...

1. 植物会释放与特定植食性昆虫取食事件对应的特异性挥发性混合物，捕食者与寄生蜂可通过学习将这类混合物与猎物建立关联，进而提升植食性昆虫的死亡率，最终改善植物的适合度，这一现象被称为间接防御（indirect defense）。
2. 植食性昆虫诱导产生的植物挥发性混合物通常同时包含快速且瞬时的绿叶挥发性物质（green leaf volatiles, GLVs），以及延迟释放且持续存在的倍半萜（sesquiterpenes）。目前已有少量实验室研究证实，昆虫可利用植物挥发性物质调控自身行为节律，但尚不明确植物挥发性混合物的时间动态特征是否以及如何影响其在间接防御中的功能。
3. 我们在自然栖息地中，对宿主植物野生烟草（Nicotiana attenuata）上的本土植食性昆虫烟草天蛾（Manduca sexta）、斑翅丽盲蝽（Tupiocoris notatus）及其天敌大眼蝽属（Geocoris spp.）的活动开展了表征分析。日间捕食者的活动仅与波动的植食性昆虫活动存在部分重叠，且在光照期（photophase）起始或结束时段遭受取食的植物，其释放的挥发性混合物会呈现出独特的绿叶挥发性物质...