Liu Zhudong, Xin Yucui, Xu Bingbing, Raffa Kenneth F, Sun Jianghua
State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beichen West Road 1-5, Chaoyang District, Beijing 100101, China,
State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beichen West Road 1-5, Chaoyang District, Beijing 100101, China.
Chem Senses. 2017 Jan;42(1):59-67. doi: 10.1093/chemse/bjw102. Epub 2016 Oct 5.
For insects that aggregate on host plants, both attraction and antiaggregation among conspecifics can be important mechanisms for overcoming host resistance and avoiding overcrowding, respectively. These mechanisms can involve multiple sensory modalities, such as sound and pheromones. We explored how acoustic and chemical signals are integrated by the bark beetle Dendroctonus valens to limit aggregation in China. In its native North American range, this insect conducts nonlethal attacks on weakened trees at very low densities, but in its introduced zone in China, it uses mixtures of host tree compounds and the pheromone component frontalin to mass attack healthy trees. We found that exo-brevicomin was produced by both female and male D. valens, and that this pheromone functioned as an antiaggregating signal. Moreover, beetles feeding in pairs or in masses were more likely than were beetles feeding alone to produce exo-brevicomin, suggesting a potential role of sound by neighboring beetles in stimulating exo-brevicomin production. Sound playback showed that an agreement sound was produced by both sexes when exposed to the aggregation pheromone frontalin and attracts males, and an aggressive sound was produced only by males behaving territorially. These signals triggered the release of exo-brevicomin by both females and males, indicating an interplay of chemical and sonic communication. This study demonstrates that the bark beetle D. valens uses sounds to regulate the production of an antiaggregation pheromone, which may provide new approaches to pest management of this invasive species.
对于聚集在寄主植物上的昆虫来说，种内吸引和反聚集分别是克服寄主抗性和避免过度拥挤的重要机制。这些机制可能涉及多种感官模式，如声音和信息素。我们探究了红脂大小蠹如何整合声学和化学信号以在中国限制聚集。在其原生北美分布区，这种昆虫以非常低的密度对衰弱树木进行非致死性攻击，但在其引入的中国分布区，它利用寄主树木化合物和信息素成分frontalin的混合物对健康树木进行大规模攻击。我们发现，雌性和雄性红脂大小蠹都能产生外短叶松素，且这种信息素起到反聚集信号的作用。此外，成对或成群取食的甲虫比单独取食的甲虫更有可能产生外短叶松素，这表明相邻甲虫发出的声音在刺激外短叶松素产生方面可能发挥作用。声音回放显示，当暴露于聚集信息素frontalin时，两性都会发出一种协调声音，这种声音会吸引雄性，而只有具有领地行为的雄性才会发出攻击性声音。这些信号会触发雌性和雄性释放外短叶松素，表明化学通讯和声音通讯之间存在相互作用。这项研究表明，红脂大小蠹利用声音来调节一种反聚集信息素的产生，这可能为这种入侵物种的害虫管理提供新方法。
