Virgin honeybee queens fail to suppress worker fertility but not fertility signalling

Queen mating status in social insects is a matter of crucial importance for workers because of its influence on the queen’s productivity and consequently their fitness. Behavioural and physiological reactions of workers to the queens mating status have been studied as a proxy to mechanisms maintaining insect sociality. Here we show that unmated honeybee queens have considerably impaired capacity to trigger worker sterility and cooperative behaviour in comparison to mated (and thus more productive) queens and that under unmated queens social harmony in honeybee societies and queen’s dominant position are somewhat compromised. Together with this it is shown that honeybee workers exposed to unmated queens despite being active reproductively and behaving accordingly display an impaired ability to advertise their fertility compared to queenless workers. These findings suggest that reproductive development, behavioural reactions and production of fertility signals are differentially regulated and differently influenced by the queen’s presence.

The effect of the queen’s presence and its mating status on the prevalence of worker ovary activation (left), and fertility signal production in fecund workers (right). MQR stands for mated queens subset and VQR for virgin queens subset.Figure optionsDownload as PowerPoint slideHighlights
► Under fecund queens and high colony productivity workers refrain from reproducing.
► Workers recognise less fitted, e.g. virgin, queens and respond by ovary activation.
► Fertile QL workers produce a fertility signal, but not if under virgin queens.
► Queen mating status regulates independently worker fertility and fertility signalling.