Absence of nepotism toward imprisoned young queens during swarming in the honey bee

Abstract

Nepotism is an important potential conflict in animal societies. However, clear evidence of nepotism in the rearing of queens in social insects is limited and controversial. In the honey bee, Apis mellifera, multiple mating by queens leads to the presence of many patrilines within each colony. When the colonies reproduce through swarming, workers rear a number of new queens, only a few of which will ultimately head a colony. Workers can potentially increase their inclusive fitness by nepotistically favoring full-sister over half-sister queens during the queen rearing and elimination process. Most studies have focused on interactions between workers and immature queens (eggs and larvae) or adult queens who have exited their queen cells. However, adult queens often remain in their queen cells for up to 1 week after emerging from their pupa. In this situation, workers prevent the queens from emerging, feed them, and protect them from other emerged queens. This stage in queen rearing is therefore one in which nepotism could occur. The current study is the first to investigate the kinship between workers and adult queens who have not emerged from their queen cells. We observed the full suite of behaviors expected during this phase of colony reproduction. Although there was no evidence for nepotism in the worker?queen interactions, there was a nonrandom distribution across patrilines of the workers interacting with the queen cells. In addition, in one colony we found differential treatment of fostered (nonkin)-queen cells.