title: Poison and alarm: the Asian hornetVespa velutinauses sting venom volatiles as an alarm pheromone.
abstract: In colonial organisms, alarm pheromones can provide a key fitness advantage by enhancing colony defence and warning of danger. Learning which species use alarm pheromone and the key compounds involved therefore enhances our understanding of how this important signal has evolved. However, our knowledge of alarm pheromones is more limited in the social wasps and hornets compared with the social bees and ants.Vespa velutinais an economically important and widespread hornet predator that attacks honey bees and humans. This species is native to Asia and has now invaded Europe. Despite growing interest inV. velutina, it was unknown whether it possessed an alarm pheromone. We show that these hornets use sting venom as an alarm pheromone. Sting venom volatiles were strongly attractive to hornet workers and triggered attacks. Two major venom fractions, consisting of monoketones and diketones, also elicited attack. We used gas chromatography coupled to electroantennographic detection (GC-EAD) to isolate 13 known and 3 unknown aliphatic ketones and alcohols in venom that elicited conspicuous hornet antennal activity. Two of the unknown compounds may be an undecen-2-one and an undecene-2,10-dinone. Three major compounds (heptan-2-one, nonan-2-one and undecan-2-one) triggered attacks, but only nonan-2-one did so at biologically relevant levels (10 hornet equivalents). Nonan-2-one thus deserves particular attention. However, the key alarm releasers forV. velutinaremain to be identified. Such identification will help to illuminate the evolution and function of alarm compounds in hornets.
authors.affiliation: Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan Province 650223, China.|University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Ya-Nan
authors.initials: YN
authors.lastname: Cheng
authors.affiliation: Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan Province 650223, China kentan@xtbg.ac.cn wenping@xtbg.ac.cn.
authors.forename: Ping
authors.initials: P
authors.lastname: Wen
authors.affiliation: Eastern Bee Research Institute, Yunnan Agricultural University, Kunming 650201, China.
authors.forename: Shi-Hao
authors.initials: SH
authors.lastname: Dong
authors.affiliation: Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan Province 650223, China kentan@xtbg.ac.cn wenping@xtbg.ac.cn.
authors.forename: Ken
authors.identifier: 0000-0002-0928-1561
authors.initials: K
authors.lastname: Tan
authors.affiliation: Division of Biological Sciences, Section of Ecology, Behavior and Evolution, University of California, San Diego, La Jolla, CA 92093, USA.
authors.forename: James C
authors.initials: JC
authors.lastname: Nieh
mesh_terms: D000374:Aggression; D000818:Animals; D001516:Bees; D001733:Bites and Stings / Q000209:etiology / Q000378:metabolism; D006801:Humans; D007659:Ketones / Q000032:analysis / Q000378:metabolism*; D010675:Pheromones / Q000737:chemistry / Q000378:metabolism*; D011042:Poisons / Q000032:analysis / Q000378:metabolism; D011235:Predatory Behavior; D014688:Venoms / Q000032:analysis / Q000378:metabolism*; D055549:Volatile Organic Compounds / Q000032:analysis / Q000378:metabolism; D014863:Wasps / Q000737:chemistry / Q000378:metabolism*
chemical_list: D007659:Ketones; D010675:Pheromones; D011042:Poisons; D014688:Venoms; D055549:Volatile Organic Compounds; C526928:undecan-2-one
keywords: Alarm pheromone; Aliphatic ketones; Hornet aggression; Sting venom; Undecen-2-one; Undecene-2,10-dinone