The division of labour between reproductive queens and mostly sterile workers is among the defining characteristics of social insects. Queen-produced chemical signals advertising her presence and fertility status, i.e. queen pheromones, are normally used to assert the queen's reproductive dominance in the colony. Most queen pheromones identified to date are chemicals that stop the daughter workers from reproducing. Nevertheless, it has long been suggested that queen pheromones could also regulate reproduction in different ways. In some multiple-queen ants with obligately sterile workers, for example—such as fire ants and pharaoh ants—queen pheromones are thought to regulate reproduction by inhibiting the rearing of new sexuals. Here, we identify the first such queen pheromone in the pharaoh ant Monomorium pharaonis and demonstrate its mode of action via bioassays with the pure biosynthesized compound. In particular, we show that the monocyclic diterpene neocembrene, which in different Monomorium species is produced solely by fertile, egg-laying queens, strongly inhibits the rearing of new sexuals (queens and males) and also exerts a weakly attractive ‘queen retinue’ effect on the workers. This is the first time that a queen pheromone with such a dual function has been identified in a social insect species with obligately sterile workers.

繁殖蚁后和大部分不育工蚁之间的分工是群居昆虫的决定性特征之一。蜂王产生的化学信号来宣传她的存在和生育状态，即蜂王信息素，通常用于断言蜂王在群体中的生殖优势。迄今为止发现的大多数蜂王信息素都是阻止后代工蚁繁殖的化学物质。尽管如此，长期以来一直有人认为女王信息素也可以以不同的方式调节繁殖。例如，在一些具有绝对不育工蚁的多蚁后蚂蚁中，例如火蚁和法老蚁，蚁后信息素被认为通过抑制新的有性蚁的繁殖来调节繁殖。在这里，我们在法老蚂蚁Monomorium pharaonis 中发现了第一个这样的女王信息素并通过纯生物合成化合物的生物测定证明其作用模式。特别是，我们表明，在不同的Monomorium物种中，单环二萜新辛布烯仅由可育的产卵蚁后产生，强烈抑制新雌性（蚁后和雄性）的繁殖，并且还发挥了弱吸引力的“蚁后随从”效应在工人身上。这是第一次在具有专性不育工蚁的群居昆虫物种中鉴定出具有这种双重功能的蜂王信息素。