The control of mosquito populations to limit their capacity to spread disease is a topic of pressing international concern, but is one that hinges on a thorough understanding of the mating ecology of these insects. In this thesis we focus on two aspects of mosquito behaviour that are central to their reproductive cycle: mate interaction and swarm formation. Much evidence indicates that mosquitoes use sound frequencies, and specifically those made by the beating wings of their neighbours, as a means to interact with one another. We investigate the role of acoustics in the aforementioned behaviours, using empirical analytical and computational approaches. We contend that a lack of existing quantitative analysis in this field has primarily been driven by the absence of sophisticated data processing tools to researchers. Vie develop a set of advanced frequency extraction techniques that can be used to investigate mosquito flight tone signals. After describing a controlled laboratory set-up that enables the acquisition of high-quality acoustic data, we introduce a signal processing framework (based on the concept of instantaneous frequency) that facilitates efficient, automated extraction of wing beat frequencies from sound recordings of individual tethered mosquitoes. Our methodology gives vast improvement in both time and frequency resolution over previous reports, and encourages the development of new analytical techniques to study flight tone properties. We extend these approaches to study pairwise interactions. We specifically test the phenomenon of harmonic convergence between mosquito couples, whereby males and females are observed to mutually tune their flight tones to some shared frequency. A thorough and exhaustive consideration of this process is provided, from a strictly data-driven perspective, with detailed comparisons to same sex interactions. We find active frequency modulation to be a salient feature of pairwise interactions. However, our data suggest a much greater diversity of interaction than has previously been considered, particularly in the same sex case.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:689693 |
| Date | January 2015 |
| Creators | Aldersley, Andrew John |
| Publisher | University of Bristol |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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