|Schneider, Stanley - UNIV. NORTH CAROLINA|
Submitted to: Insectes Sociaux
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 28, 2008
Publication Date: December 4, 2007
Citation: Schneider, S.S., DeGrandi-Hoffman, G. 2008. Queen replacement in African and European honey bee colonies with and without afterswarms. Insect Sociaux 55:79-85. Interpretive Summary: Honey bee colonies reproduce by swarming. When a colony becomes overcrowded, worker bees begin producing new queens in preparation for swarming. When the first queen emerges, the reigning queen and several thousand workers leave the hive to establish a new colony. In some instances, additional queens emerge and leave the hive with several thousand workers. These are called 'afterswarms'. We conducted a series of studies using European and African bees to determine whether the time needed for queen replacement, the effects of queen emergence order, and worker-queen interactions differed between colonies that did and did not produce afterswarms. We found in both African and European bees that if a single swarm was issued from a colony, the first queen to emerge had the best chance of becoming the new queen in the colony, and the entire queen replacement process took from 24-48 hrs. The interactions between newly emerged queens and workers were directed primarily toward queens that emerged first. If there were afterswarms, the queen replacement process required 5-6 days. Queens that emerged first had no advantage in survivorship or in their chances of becoming the new queen over those emerging later. Worker-queen interactions were much more frequent when there were afterswarms and were directed to all queens. The difference in worker-queen interactions in colonies that did and did not produce afterswarms indicates that worker behavior is the primary determinant for both the outcome of queen replacement and the choice of who will be the new queen in the colony.
Technical Abstract: We examined the dynamics of the queen replacement process in African and European colonies that did and did not produce afterswarms. If colonies did not produce afterswarms, the queen replacement process was completed in 24-48 hours, the first-emerging virgin queen (VQ) typically inherited the natal nest even if multiple queens emerged, workers performed few vibration signals on emerged queens, and all signaling activity was directed toward early emerging VQs. In contrast, if colonies did produce afterswarms, the queen replacement process required 5-6 days, there was no advantage for first-emerging queens, vibration rates on emerged queens were 25 times greater, and signaling activity was typically directed toward all emerged VQs. Although vibration signal activity was more pronounced in colonies with afterswarms, the signal was consistently associated with increased VQ survival under all conditions. These trends were exhibited similarly in the African and European colonies, suggesting that they have broad applicability to queen-replacement decisions over a range of environmental and racial conditions. However, the African and European colonies differed in the total number of queens involved in the elimination process and the relative importance of queen duels and pre-emergence destruction under the different reproductive strategies. Taken together, our results suggest that worker behavior is the primary determinant for the outcome of queen replacement, either through reduced interactions that allow first-emerged queens to rapidly eliminate rivals, or through increased use of interactions such as the viration signal, which allow workers to influence the ultimate fate of each emerged VQ. We discuss the possibility that these behavior patterns may reflect the roles of cooperation and conflict in shaping honey bee reproductive decisions.