Decoding the Behavior of a Queenless Colony Using Sound Signals

SIMPLE SUMMARY: In the last decade, a large decline of honey bee colonies has been observed, caused by multiple factors that may affect them and contribute to their total extinction. Therefore, it is of the utmost importance to find successful ways of extensively monitoring beehives’ status in order to detect potential threats. In this context, one of the states of a bee colony that should be monitored is the queenless state, so in the present research, we tried to investigate the behavior of honeybees during their queen’s loss through recording and analyzing sound data from beehives over a certain period. ABSTRACT: Honeybees are reported to be the most vital pollinators of agricultural and horticultural crops. However, their widespread decline has raised great attention to the need to monitor their activity in order to identify the causes and implement countermeasures. The recording and analysis of signals used by honeybees for their communication in their hive can be a very helpful tool to the beekeepers for the remote control of the hives. Thus, in the present study, we used a set of sound recording data taken inside the hives to automatically detect the sounds of the bees over a certain period, to distinguish between queenright and queenless states, and to find the gradual changes in the queenless state. Unlike what was commonly believed, noticeable changes in the sound signals of all experimental colonies were observed just one hour after the queens’ removal from the hive, while the sound signals were intensified over a period of 5 h, after which the transmitted signal stabilized to the equivalent of a queenless state. The colonies seemed to return to their normal sounds 9–10 days after the reintroduction of the queens in the hives. Our study concluded that timely intervention of the queen’s absence combined with the immediate intervention of the beekeeper may be a determining factor in mitigating the adverse effects that occur from the queen’s loss.