Data from: Poison and alarm: the Asian hornet Vespa velutina uses sting venom volatiles as alarm pheromone

In colonial organisms, alarm pheromones can provide a key fitness advantage by enhancing colony defense 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 as compared to the social bees and ants. Vespa velutina is an economically important and widespread hornet predator that attacks humans and honey bees. This species is native to Asia and has now invaded Europe. Despite growing interest in V. velutina, it was unknown if 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 GC-EAD and identified 13 known and three 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 for V. velutina remain to be identified. Such identification will help to illuminate the evolution and function of alarm compounds in hornets.

在群居生物中，报警信息素（alarm pheromone）可通过强化群体防御与预警危险，为种群带来关键的适合度优势。因此，明确哪些物种会使用报警信息素及其关键组分，有助于我们深入理解这一重要信号的演化历程。然而，相较于群居蜜蜂与蚂蚁，学界对群居胡蜂和大黄蜂报警信息素的认知仍较为有限。黄脚胡蜂（Vespa velutina）是一类经济影响显著、分布广泛的捕食性胡蜂，会攻击人类及蜜蜂。该物种原产于亚洲，目前已入侵欧洲地区。尽管学界对黄脚胡蜂（Vespa velutina）的研究热度日益攀升，但此前尚不清楚其是否拥有报警信息素。本研究证实，这类胡蜂会将螫针毒液作为报警信息素使用。螫针毒液中的挥发性物质对胡蜂工蜂具有极强的吸引作用，且可触发攻击行为。毒液中两类主要组分——分别为单酮类与二酮类化合物——同样可引发攻击行为。本研究采用气相色谱-触角电位联用技术（GC-EAD），在毒液中鉴定出13种已知与3种未知的脂肪族酮类及醇类化合物，这些化合物均可引发胡蜂触角的显著电位反应。其中两种未知化合物可能为十一烯-2-酮与十一碳烯-2,10-二酮。三种主要化合物——2-庚酮、2-壬酮与2-十一酮——均可触发攻击行为，但仅2-壬酮在符合生物学相关的浓度下（10倍胡蜂当量）可引发该反应。因此，2-壬酮值得重点关注。然而，黄脚胡蜂关键的报警信号释放物质仍有待鉴定。完成此类鉴定将有助于阐明胡蜂报警化合物的演化历程与功能。