Alternative reproductive tactics in social wasps

Accleton, Christopher (2019) Alternative reproductive tactics in social wasps. Doctoral thesis (PhD), University of Sussex.

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Abstract

There is an abundance of different behavioural approaches, or tactics, employed by animals to maximise reproductive success in different situations. The best documented alternative reproductive tactics (ART) have mainly been those carried out by males. In this thesis I use field data and molecular genotyping to investigate ARTs carried out by females in two very different species of social wasps.
In Chapter 1, I explore the topic of alternative reproductive tactics in insects, and introduce my two study systems, Polistes dominula and Ammophila pubescens. In Part I of this thesis (Chapters 2 - 3), I focus on ARTs in foundress associations of the primitively eusocial paper wasp P. dominula. In these associations, there is a dominance hierarchy in which the rank 1 female lays most or all of the eggs. In Chapter 2 I use data from a Spanish field site to investigate the rules involved in establishing the dominance hierarchy. Specifically, how two potential ARTs, where a female either initiates a nest of her own, or joins an existing nest, affect reproductive status. I show that being the female that first initiates the nest is the most important predictor of attaining rank 1 reproductive status within the P.dominula hierarchy, but that body size might also be important. Following this, in Chapter 3 I compare characteristics of multi-female nests originally initiated by either a solitary foundress or a group of foundresses. I show that nest founding tactic may indirectly affect both productivity and survival through its effect on group size.
In Part II of this thesis (Chapter 4), I focus on ARTs in the solitary nesting subsocial digger wasp A. pubescens. A. pubescens females produce a sequence of nests, each containing a single offspring that is provisioned with paralysed caterpillars. In Chapter 4 I investigate the factors influencing the occurrence of intraspecific parasitism, whereby a female removes the egg of a conspecific host and replaces it with an egg of her own. I show that parasites do not restrict their selection of host’s nests to those in the locality of their own nests, but instead parasisitze throughout the aggregation.
In Chapter 5, I first introduce a framework inspired by the well-developed sex-allocation literature, in which ARTs can be distinguished based on when and how tactic-specific phenotypic determination occurs. Next, I summarise my key findings and attempt to characterize the ARTs in my study systems within the aforementioned framework. Finally, I comment on future possible directions for research in this area.

Item Type: Thesis (Doctoral)
Schools and Departments: School of Life Sciences > Biology and Environmental Science
Subjects: Q Science > QL Zoology > QL0360 Invertebrates > QL0434 Arthropoda > QL0463 Insects > QL0563 Hymenoptera
Depositing User: Library Cataloguing
Date Deposited: 03 May 2019 10:51
Last Modified: 03 May 2019 11:18
URI: http://sro.sussex.ac.uk/id/eprint/83520

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