Manipulating two olfactory cues causes a biological control beetle to shift to non-target plant species

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.
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 ...

嗅觉信号（Olfactory cues）可决定植食性昆虫的宿主偏好，但其在宿主转换（host shifting）中的作用尚不明确。宿主专一性（host specificity）与宿主转换潜力是入侵植物生物防治剂（biological control agents）筛选及释放后评估的重要标准。然而，嗅觉信号在介导生物防治剂宿主转换中的作用尚未得到充分理解。

为探究嗅觉信号在据称单食性的跳甲（Agasicles hygrophila，入侵植物空心莲子草Alternanthera philoxeroides的重要生物防治剂）宿主选择中的作用，我们提取并分析了宿主植物空心莲子草及非宿主植物Alternanthera sessilis、Beta vulgaris和Amaranthus mangostanus产生的挥发性物质（volatiles）。此外，我们采用电生理技术（electrophysiological techniques）、行为生物测定（behavioural bioassays）及田间试验，测试了A. hygrophila对不同植物挥发性物质组合的触角反应（antennal responses）与行为偏好（behavioural preferences），以及...