‘Beeing’ part of a group: Group and individual decision-making in honeybeesKatie WhartonBirds and bees…but mostly the beesGroup decision-makingFlock of StarlingsThe honeybee colony’s investment in males (drones)“The drone is a filthy, gluttonous creature. He is everything that the worker is not. Like an imposing knight in medieval armor, with his silky antennae, and golden-colored hairs adorning his thorax, he looks more imposing than he is useful.”- Louis Sutherland, The Life of the Queen BeeBy producing drones, a colony invests in reproductionOverview Background:Honeybee colonies regulate their production of drones Question 1:Does the queen regulate her production of drone eggs? Question 2:Do the workers regulatethe number of drone larvae they rear? Conclusions & future directionsColony size influences reproductionSeason influences reproductionSpring Summer FallSwarmingWorkers kick out drones# drones in colony+ foodSeeley & Mikheyev, 2003Food availability influences reproduction+ drones - dronesFree & Williams, 1975Current investment in reproduction influences future reproductionColony drone production is influenced by… Colony size Season Food availability Drones present in hive Drone production is regulated adaptivelyFrom the colony to the individualsOverview Background:Honeybee colonies regulate their production of drones Question 1:Does the queen regulate her production of drone eggs? Question 2:Do the workers regulatethe number of drone larvae they rear? Conclusions & future directionsHaplodiploidyFertilize egg?yes noHow a bee colony produces a drone15-20% droneDoes the queen regulate her production of drone eggs?Predictions:  The queen’s production of drone eggs will depend on how many drone eggs she recently laid The queen’s production of drone eggs will be NOT be determined only by the number of drone cells availableWWDDStage 1Stage 2Drone egg production decreasedwhen queens recently laid drone eggsQueens did not recently lay drone eggsQueens recently laiddrone eggsnsp<0.05WDOverview Background:Honeybee colonies regulate their production of drones Question 1:Does the queen regulate her production of drone eggs?-YES Question 2:Do the workers regulatethe number of drone larvae they rear? Conclusions & future directionsObservations: the case of the missing drone broodWhen times are “bad,”the workers will destroy drone brood in the colonyLots of anecdotal accounts…No experiments!Do the workers regulate the number of drone larvae they rear?Predictions:  The workers’ tendency to rear drone larvae will depend on how many drones are already in the colony The worker’s rearing of drone larvae will NOT be determined only by the presence of drone eggs laid by the queenDWDWWWDWDDDWDrone brood addedWorker brood addedSurvival of immatures:= proportion of eggs that were reared Calculated for workers and dronesWDDrone survival was lowerwhen colonies were provided with drone broodDrone brood removedDrone brood addedWDp<0.01nsOverview Background:Honeybee colonies regulate their production of drones Question 1:Does the queen regulate her production of drone eggs?-YES Question 2:Do the workers regulatethe number of drone larvae they rear?-YES Conclusions & future directionsConclusions Honeybee colonies are exceptionally good at regulating drone production This adaptive regulation arises through an interplay of decisions by individuals in the colonyConclusionsIf the colony already has plenty of drones: The queen lays fewer drone eggs- She is not constrained by the comb patterns built by the workers The workers selectively eliminate immature drones- They are not constrained by the egg-laying decisions of the queenHow might this be beneficial to the colony?Multiple stages of flexibilityAdditional lines of studyColony drone production depends on… Colony size Season Food availability Drone brood present in hive ???Additional lines of study Annually:200,000 workers2 virgin queenseach queen mates with ~18 males20,000 drones! Why do colonies produce so many drones?The ups…Thanks for “beeing” there to help! CommitteeTom Getty, Fred Dyer, Kay Holekamp, Zach Huang Getty lab membersLindsey Walters, Ben Janse, Eva Lewandowski, Jean Johnson Dyer lab membersFrank Bartlett, Steph Kortering, Mercedes Ramirez,John Townsend-Mehler, Cindy Wei Summer field assistantsLora Bramlett, Kim Davis, Mara Trudgen, Andy Taylor, Adam Bates, Liz Dean, Jared Ruddick, Kourtney Trudgen, Megan Wheeler, Michael Hillman, Jenn Lieb, Erin Walaszczyk, Sara Kaltz MSU Department of Zoology MSU College of Natural Science MSU EEBB program NSF IGERT program in sequential