Rottler-Hoermann Ann-Marie, Schulz Stefan, Ayasse Manfred
Institute of Evolutionary Ecology and Conservation Genomics , University of Ulm , Ulm, Germany.
Institute of Organic Chemistry , Technical University Braunschweig , Braunschweig, Germany.
R Soc Open Sci. 2016 Jan 6;3(1):150599. doi: 10.1098/rsos.150599. eCollection 2016 Jan.
Social insects are well known for their high level of cooperation. Workers of the primitively eusocial bumblebee Bombus terrestris are able to produce male offspring in the presence of a queen. Nonetheless, they only compete for reproduction, in the so-called competition phase, when the workforce is large enough to support the rearing of reproductives. So far, little is known about the proximate mechanisms underlying the shift between altruism and selfish behaviour in bumblebee workers. In this study, we have examined the influence of chemical cues from the nest wax on the onset of worker reproduction. Chemical analyses of wax extracts have revealed that the patterns and amounts of cuticular lipids change considerably during colony development. These changes in wax scent mirror worker abundance and the presence of fertile workers. In bioassays with queen-right worker groups, wax affects the dominance behaviour and ovarian development of workers. When exposed to wax from a colony in competition phase, workers start to compete for reproduction. We suggest that wax scent enables workers to time their reproduction by providing essential information concerning the social condition of the colony.
群居昆虫以其高度的合作水平而闻名。原始真社会性的地熊蜂工蜂在有蜂王的情况下能够产生雄性后代。然而，它们只在所谓的竞争阶段争夺繁殖机会，即当工蜂数量足够多以支持繁殖个体的养育时。到目前为止，关于熊蜂工蜂利他行为和自私行为之间转变的近因机制知之甚少。在这项研究中，我们研究了巢蜡中的化学信号对工蜂繁殖开始的影响。蜡提取物的化学分析表明，表皮脂类的模式和数量在蜂群发育过程中发生了相当大的变化。蜡气味的这些变化反映了工蜂数量以及可育工蜂的存在情况。在有蜂王的工蜂群体的生物测定中，蜡会影响工蜂的支配行为和卵巢发育。当接触处于竞争阶段的蜂群的蜡时，工蜂开始争夺繁殖机会。我们认为，蜡气味通过提供有关蜂群社会状况的重要信息，使工蜂能够安排它们的繁殖时间。
