title: Sound-Triggered Production of Antiaggregation Pheromone Limits Overcrowding of Dendroctonus valens Attacking Pine Trees.
abstract: 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.
authors.affiliation: 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, sunjh@ioz.ac.cn.
authors.forename: Zhudong
authors.initials: Z
authors.lastname: Liu
authors.affiliation: 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.|Institute of Health, Anhui University, Hefei 230039, China and.
authors.forename: Yucui
authors.initials: Y
authors.lastname: Xin
authors.affiliation: 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.
authors.forename: Bingbing
authors.initials: B
authors.lastname: Xu
authors.affiliation: Department of Entomology, University of Wisconsin, Madison, 53706 WI, USA.
authors.forename: Kenneth F
authors.initials: KF
authors.lastname: Raffa
authors.affiliation: 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.
authors.forename: Jianghua
authors.initials: J
authors.lastname: Sun
mesh_terms: D000818:Animals; D001517:Coleoptera / Q000502:physiology*; D005260:Female; D008297:Male; D010675:Pheromones / Q000096:biosynthesis / Q000378:metabolism*; D028223:Pinus / Q000469:parasitology*; D013016:Sound
chemical_list: D010675:Pheromones
keywords: 
  Dendroctonus valens
  ; 
  exo-brevicomin; antiaggregation; bark beetle; sound