title: Cheaters sometimes prosper: targeted worker reproduction in honeybee (Apis mellifera) colonies during swarming.
abstract: Kin selection theory predicts that honeybee (Apis mellifera) workers should largely refrain from producing their own offspring, as the workers collectively have higher inclusive fitness if they rear the sons of their mother, the queen. Studies that have quantified levels of ovary activation and reproduction among workers have largely supported this prediction. We sampled pre-emergent male pupae and adult workers from seven colonies at regular intervals throughout the reproductive part of the season. We show that the overall contribution of workers to male (drone) production is 4.2%, nearly 40 times higher than is generally reported, and is highest during reproductive swarming, when an average of 6.2% of the males genotyped are worker-produced. Similarly, workers in our samples were 100 times more likely to have active ovaries than previously assumed. Worker reproduction is seasonally influenced and peaks when colonies are rearing new queens. Not all worker subfamilies contribute equally to reproduction. Instead, certain subfamilies are massively over-represented in drone brood. By laying eggs within the period in which many colonies produce virgin queens, these rare worker subfamilies increase their direct fitness via their well-timed sons.
authors.affiliation: Behaviour and Genetics of Social Insects Laboratory, School of Biological Sciences, University of Sydney, Macleay A12, Science Road, Sydney, NSW, 2006, Australia.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Holmes
authors.affiliation: Behaviour and Genetics of Social Insects Laboratory, School of Biological Sciences, University of Sydney, Macleay A12, Science Road, Sydney, NSW, 2006, Australia.
authors.forename: Benjamin P
authors.initials: BP
authors.lastname: Oldroyd
authors.affiliation: Behaviour and Genetics of Social Insects Laboratory, School of Biological Sciences, University of Sydney, Macleay A12, Science Road, Sydney, NSW, 2006, Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Duncan
authors.affiliation: Honeybee Research Section, ARC-Plant Protection Research Institute, Private Bag X5017, Stellenbosch, 7599, South Africa.
authors.forename: Michael H
authors.initials: MH
authors.lastname: Allsopp
authors.affiliation: Behaviour and Genetics of Social Insects Laboratory, School of Biological Sciences, University of Sydney, Macleay A12, Science Road, Sydney, NSW, 2006, Australia.
authors.forename: Madeleine
authors.initials: M
authors.lastname: Beekman
mesh_terms: D000818:Animals; D001516:Bees / Q000235:genetics* / Q000502:physiology*; D005260:Female; D005838:Genotype; D008297:Male; D011679:Pupa / Q000235:genetics; D012098:Reproduction / Q000235:genetics / Q000502:physiology; D012726:Sexual Behavior, Animal / Q000502:physiology*; D012919:Social Behavior
keywords: Apis mellifera; anarchy; reproductive parasitism; reproductive swarming; worker reproduction