Influence of brood pheromone on honey bee colony establishment and queen replacement

There is both anecdotal and empirical evidence to suggest that honey bee queen longevity has decreased in recent years, leading to premature supersedure and queen failure. This is particularly evident when beekeepers create new colonies from packages, where many queens are immediately rejected or replaced after only a few weeks. Relatively little is known about the mechanisms that trigger supersedure in honey bees, although previous studies have shown a strong link with open brood suggesting that brood ester pheromone (BEP) may be involved. We installed new packages into hive equipment with either no treatment (Control), exposure to BEP during package transport and for the first 10 days after installation (BEP), or one frame of open brood (Brood). We found that over the course of the 12-week experiment, Control colonies grew the least, Brood colonies started stronger but leveled off similar to Control colonies, and BEP colonies grew slowly initially but continued positive growth through the end of the experiment. Moreover, we found a highly significant effect of treatment on Outcome—whether the initial queens were immediately Rejected (within 5 weeks), Superseded (after 5 weeks), or Accepted, with Brood, BEP, and Control colonies having 86.7%, 53.3%, and 33.3% acceptance, respectively. Finally, we found that the open-brood:adult-bees ratio significantly diverged 3 weeks prior to queen replacement between accepting and replacing colonies. We suggest that while BEP alone is insufficient to deter premature supersedure, there are clear benefits to queen longevity and package-installation success when establishing new colonies with frames of young brood.