View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by University of East Anglia digital repository Colony Life History in the Bumble Bee Bombus terrestris: Interactions, Timing and Control. Jacob George Holland BSc (Hons) Thesis submitted for the degree of Doctor of Philosophy University of East Anglia School of Biological Sciences December 2013 This copy of the thesis has been supplied on condition that anyone who consults it is understood to recognise that its copyright rests with the author and that use of any information derived there from must be in accordance with current UK Copyright Law. In addition, any quotation or extract must include full attribution. Thesis abstract The evolutionary success of organisms is dependent on adaptive life histories, but the mechanistic control of life history traits is not often studied from an evolutionary perspective. One fascinating area with the potential to advance the understanding of life history regulation in an evolutionary context is the eusocial insects, since their colonies can themselves be regarded as possessing life histories. This is because whole colonies must develop and reproduce effectively in order to pass on the genes of their members. However, as not all colony members have the same fitness optima for colony life history traits, conflict can exist over the control of these traits. Furthermore, colony traits may respond differently to the external environment than in individual organisms, because affecting the life history of colony members might not have corresponding effects on the life history of whole colonies. In this thesis, I use laboratory experiments with the bumble bee Bombus terrestris to investigate the control of eusocial insect colony life history, with a focus on the interactions that bring about control over timing. Specifically, I reveal queen control over the onset of male production; show that colonies do not differ over colony development in their response to natal or non-natal worker laid eggs; demonstrate that higher temperature increases the productivity, but not longevity, of individuals and colonies; and find that foraging gene expression in queens may be linked to colony establishment. Taken together, these findings advance the understanding of life history and social evolution by illuminating processes at behavioural and molecular levels which regulate colony life history in eusocial insects. Furthermore, I discuss how this research has potential applications for the ecological and commercial management of bumble bees, which are key pollinators of crops and wild flowers. 2 Chapter contributions and publication All parts of this thesis have been written by Jacob Holland, in consultation with Andrew Bourke (and with David Collins for the methods of Chapter 5). Estimates of approximate percentage contributions to the initial concepts, planning, conducting (data collection) and analyses of the experiments included in each thesis data chapter (2-5) are given below. The publication status of the findings presented in each data chapter is also given. Chapter 2: published, in largely the same format, as: Holland JG, Guidat FS, Bourke AFG (2013) Queen control of a key life-history event in a eusocial insect. Biology Letters 9:20130056 Concept: Jacob Holland 50%; Andrew Bourke 50% Planning: Jacob Holland 70%; Andrew Bourke 30% Conducting: Jacob Holland 85%; Florian Guidat 15% (genotyping service provided by the John Innes Centre, Norwich Research Park, Norwich, UK) Analysis: Jacob Holland 90%; Andrew Bourke 10% Chapter 3: not yet published Concept: Lorenzo Zanette 50%; Andrew Bourke 50% Planning: Lorenzo Zanette 30%; Andrew Bourke 30%; Jacob Holland 20%; Tulio Nunes 20% Conducting: Jacob Holland 50%; Tulio Nunes 50% Analysis: Jacob Holland 90%; Tulio Nunes 10% Chapter 4: not yet published Concept: Jacob Holland 60%; Andrew Bourke 40% Planning: Jacob Holland 70%; Andrew Bourke 30% Conducting: Jacob Holland 70%; Cameron Stables 15%; Rachel Turner 10%; Peter Higgins 5%. Analysis: Jacob Holland 100% Chapter 5: not yet published Concept: Jacob Holland 40%; Andrew Bourke 40%; David Collins 20% Planning: Jacob Holland 40%; David Collins 40%; Andrew Bourke 20% Conducting: Jacob Holland 40%; David Collins 40%; Faaziah Chishty 20% (qPCR service provided by qStandard, UCL, London, UK) Analysis: Jacob Holland 90%; David Collins 10% 3 Contents Thesis abstract ...................................................................................................... 2 Chapter contributions and publication .................................................................... 3 List of figures and tables ........................................................................................ 6 Acknowledgements ................................................................................................ 7 Chapter 1 ...................................................................................................................... 8 Life history in eusocial insects and bumble bees ....................................................... 8 Life history in eusocial insects ............................................................................... 8 Life History in bumble bees .................................................................................. 19 Thesis aims ......................................................................................................... 22 Outline of data chapters ....................................................................................... 22 Chapter 2 .................................................................................................................... 25 Queen control of colony sexual maturation in the bumble bee Bombus terrestris .... 25 Abstract ............................................................................................................... 25 Introduction .......................................................................................................... 26 Materials & Methods ............................................................................................ 27 Results ................................................................................................................ 32 Discussion ........................................................................................................... 35 Chapter 3 .................................................................................................................... 41 Worker policing of eggs and intraspecific social parasitism in the bumble bee Bombus terrestris .................................................................................................... 41 Abstract ............................................................................................................... 41 Introduction .......................................................................................................... 42 Materials & Methods ............................................................................................ 45 Results ................................................................................................................ 49 4 Discussion ........................................................................................................... 51 Chapter 4 .................................................................................................................... 58 Effects of temperature on colony life history in the bumble bee Bombus terrestris .. 58 Abstract ............................................................................................................... 58 Introduction .......................................................................................................... 59 Materials & Methods ............................................................................................ 62 Results ................................................................................................................ 71 Discussion ........................................................................................................... 75 Chapter 5 .................................................................................................................... 91 The role of the foraging gene and queen locomotor behaviour at colony foundation in the bumble bee Bombus terrestris ........................................................................... 91 Abstract ............................................................................................................... 91 Introduction .......................................................................................................... 92 Materials & Methods ............................................................................................ 95 Results .............................................................................................................. 103 Discussion ......................................................................................................... 105 Chapter 6 .................................................................................................................. 117 General conclusions .............................................................................................. 117 Main findings ..................................................................................................... 117 Importance for social evolution .........................................................................