Virgin queens selectively destroy fully matured queen cells in the honeybee Apis mellifera L

Experiments were carried out to determine how newly emerged virgin queens destroy queen cells with broods which will be competitors for the succession of the colony. When queen cells with older, 13-day-old broods set to emerge within 1 day were presented together with those of younger broods to workers and newly emerged queens in the colony, we found that the older queen cells were preferentially destroyed. It was also shown that a virgin queen destroyed the queen cells with older brood (12-13 days old) first when they were presented together with cells with younger broods (9-10 days old) simultaneously in the experimental cage. However, no significant preference was detected in the destruction between queen cells with 10- and 7-day-old broods. We concluded that virgin queens selectively destroy the queen cells housing broods which will emerge shortly. The possibility that by the selective destruction of older queen cells, newly emerged queens can reduced their risks including death that might otherwise be caused by fights with competitors was discussed.