Manipulating two olfactory cues causes a biological control beetle to shift to non-target plant species
Manipulating two olfactory cues causes a biological control beetle to shift to non-target plant species
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操纵两个嗅觉线索导致生物防治甲虫转向非目标植物物种
DOI：
10.1111/1365-2745.12778
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发表时间：
2017-11-01
影响因子：
5.5
通讯作者：
Ma, Rui-Yan
中科院分区：
文献类型：
--
作者：
Li, Na;Li, Shuang;Ma, Rui-Yan
1. 嗅觉线索可以决定食草昆虫的寄主偏好，但它们在寄主转移中的作用尚不清楚。寄主特异性和寄主转移的可能性是筛选和释放后评价入侵植物生物防治剂的重要标准。然而，嗅觉线索在生物防治剂中介导宿主转移中的作用尚不清楚。为了研究嗅觉信号在单食蚤甲虫（agagicles hygrophila）选择寄主中的作用，我们提取并分析了单食蚤甲虫（agagicles philoeroides）和非寄主植物Alternanthera sessilis、Beta vulgaris和Amaranthus mangostanus产生的挥发物。此外，我们使用电生理技术、行为生物测定和田间试验来测试嗜湿蝽对不同植物挥发物和处理组合以及不同剂量和组合的纯化合物的触角反应和行为偏好。研究结果表明，嗜湿甲雌虫确实利用嗅觉线索来选择取食和产卵的植物，并且在第二偏好的非寄主植物-嗜湿甲（a . philoxeroides）的近亲上，其幼虫的存活率超过75%。虽然雌性甲虫对来自寄主和非寄主植物的许多挥发性化合物都有反应，但(E)-4,8-二甲基-1,3,7-非atriene （DMNT）对甲虫的取食和产卵偏好有积极的促进作用，而(Z)-3-己烯醇则表现出驱避作用。值得注意的是，在田间试验中，(Z)-3-己烯醇对寄主植物或DMNT对非寄主植物的互补试验显著改变了嗜水单胞虫对非寄主植物的偏好，并导致非寄主植物无尾蚜的产卵和卵孵化。合成。我们展示了一种嗅觉机制，通过这种机制，一种特殊的食草甲虫使用两种常见植物挥发物的比例，(E)-4,8-二甲基-1,3,7-壬三烯和(Z)-3-己烯，来区分自然界中的寄主和非寄主植物。这项研究强调了嗅觉线索可能导致生物防治剂中不希望的宿主范围扩大的重要机制，从而代表了对常见生物防治剂跳蚤甲虫的宿主转移和侵袭性发展潜力的重要警告。
1. Olfactory cues can determine the host preferences of herbivorous insects, but their role in host shifting is unclear. Host specificity and the potential for host shifts are important criteria for screening and post-release evaluation of biological control agents for invasive plants. However, the role of olfactory cues in mediating host shifts in biological control agents is not well understood.2. To investigate the role of olfactory cues in host selection of a reportedly monophagous flea beetle (Agasicles hygrophila), an important biocontrol agent for invasive alligator weed (Alternanthera philoxeroides), we extracted and analysed the volatiles produced by the host-plant A. philoxeroides and the non-host plants Alternanthera sessilis, Beta vulgaris and Amaranthus mangostanus. Moreover, we used electrophysiological techniques, behavioural bioassays and field trials to test the antennal responses and behavioural preferences of A. hygrophila to combinations of different plant volatiles and treatments, and pure compounds in different dosages and combinations.3. We show that A. hygrophila female beetles indeed use olfactory cues to select plants for feeding and oviposition and that the survivorship of larvae on the second preferred non-host plant A. sessilis, a close relative of the first preferred host plant A. philoxeroides, was over 75% in a field trail. Although female beetles responded to many volatile compounds from host and non-host plants, (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) positively encouraged the beetle's feeding and oviposition preferences, whereas (Z)-3-hexenol displayed repellent effect. Remarkably, complementation assays with (Z)-3-hexenol on host plant or DMNT on non-host plants significantly shifted A. hygrophila host preferences to non-host plants and resulted in oviposition and egg hatching on the non-host plant A. sessilis in field trials.4. Synthesis. We demonstrate an olfactory mechanism by which a specialized herbivorous beetle uses the ratio of two common plant volatiles, (E)-4,8-dimethyl-1,3,7-nonatriene and (Z)-3-hexenol, to discriminate between its host and non-host plants in nature. This study highlights an important mechanism by which olfactory cues could lead to undesired host range expansion in biocontrol agent, thus representing an important warning of the potential for a host shift and development of invasiveness in a common biocontrol agent, the flea beetle.