The attraction of Spodoptera frugiperda neonates to cowpea seedlings is mediated by volatiles induced by conspecific herbivory and the elicitor inceptin
The attraction of Spodoptera frugiperda neonates to cowpea seedlings is mediated by volatiles induced by conspecific herbivory and the elicitor inceptin
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DOI：
10.1007/s10886-007-9414-y
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发表时间：
2008-03-01
影响因子：
2.3
通讯作者：
Teal, Peter E. A.
中科院分区：
文献类型：
--
作者：
Carroll, Mark J.;Schmelz, Eric A.;Teal, Peter E. A.
新生秋季粘虫[一汽;草地贪夜蛾[Spodoptera frugiperda（Smith）]在从卵块分散到初始取食点时经常遇到同种草食动物的损害。我们研究了分散新生儿的方向反应，草食动物的损害豇豆幼苗，特别是研究新生儿的行为是否受到inceptin，FAW诱导的豇豆叶片防御的主要激发子的影响。我们专注于同种第一龄幼虫造成的损害的反应，可能会发生在传播的兄弟姐妹从卵块。破坏第一龄FAW的Inceptin含量控制通过他们的饮食，与叶喂养的FAW产生inceptin在他们的口腔分泌物，和根喂养或饥饿FAW缺乏这些激发子。在一个生物测定设计，以评估新生儿扩散关闭宿主植物，新生儿的百分比较高，仍然对草食动物诱导或inceptin处理的植物比未受损的植物，机械损坏的植物，新鲜损坏的植物，或对植物损坏的FAW缺乏inceptin。进一步调查的新生儿植物气味的反应与四臂嗅觉仪表明，新生儿的吸引力的气味从4小时的老一汽损害强烈依赖于以前的饮食的破坏性幼虫。新生儿被吸引到气味从4小时老一汽损坏的气味从未受损的植物或新鲜一汽的损害，提供了破坏性的幼虫以前摄取的叶材料。在诱导植物的气味的直接比较中，被叶饲FAW损害的植物与用合成inceptin处理的植物一样有吸引力。经GC-MS分析，确定FAW草食性害虫挥发性成分主要为（E）-4，8-二甲基-1，3，7-壬三烯（DMNT）。虽然DMNT和未受损的植物气味比空气更有吸引力，新生儿更喜欢DMNT补充植物气味。这些结果表明，新生FAW利用植食性诱导的植物挥发物作为寄主植物的位置和识别线索。
Neonate fall armyworms [FAW; Spodoptera frugiperda (Smith)] often encounter conspecific herbivore damage as they disperse from an egg mass to an initial feeding site. We investigated the orientation responses of dispersing neonates to herbivore damage in cowpea seedlings, specifically examining whether neonate behaviors were affected by inceptin, the primary elicitor of FAW-induced defenses in cowpea leaves. We focused on responses to damage caused by conspecific first instars, as might occur during the dispersal of siblings from an egg mass. Inceptin contents of damaging first instar FAW were controlled through their diets, with leaf-fed FAW producing inceptins in their oral secretions, and root-fed or starved FAW lacking these elicitors. In a bioassay designed to evaluate neonate dispersal off a host plant, a higher percentage of neonates remained on herbivore-induced or inceptin-treated plants than on undamaged plants, mechanically damaged plants, freshly damaged plants, or on plants damaged by FAW lacking inceptins. Further investigations of neonate responses to plant odors with a four-arm olfactometer demonstrated that neonate attraction to odors from 4-h old FAW damage was strongly dependent on previous diet of the damaging larvae. Neonates were attracted to odors from 4-h old FAW damage over odors from undamaged plants or fresh FAW damage, provided that the damaging larvae had previously ingested leaf material. In a direct comparison of odors from induced plants, plants damaged by leaf-fed FAW were as attractive as plants treated with synthetic inceptin. GC-MS analysis confirmed that (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) was the major volatile induced by FAW herbivory. While both DMNT and undamaged plant odors were more attractive than air, neonates preferred DMNT-supplemented plant odors. These results suggest that neonate FAW exploit herbivore-induced plant volatiles as host plant location and recognition cues.