No organism evolves in isolation; the symbiotic microorganisms associated with
insects are key determinants of their hosts ecology and evolution. This thesis
investigates the fungal communities found with bark and ambrosia beetles
(Curculionidae: Scolytinae & Platypodinae) in an attempt to better understand the
diversity and variability of this ecologically and economically important system. I
start by assessing the efficacy of high throughput sequencing (HTS) and
metabarcoding for the characterisation of fungal communities derived from whole
arthropod DNA extracts (Chapter 2). I then apply this approach to understanding
the biotic and abiotic determinants of beetle associated fungal taxa, and find that
both beetle species identity and environmental conditions significantly predict
community richness and composition (Chapter 3). In Chapter 4, I expand upon the
beetle species level differences in microbial communities to show that they are
driven by a relatively small subset of fungal taxa, predominantly belonging to the
beetle associated Microascales, but also to the relatively unexplored
Saccharomycetes. I further apply HTS to the recreation of beetle evolutionary
histories using mitochondrial genomics, and test for correlations between beetle
phylogenetic and mycobiotic similarities (Chapter 5). My investigations demonstrate
the utility of recently developed sequencing technologies to the study of microbial
symbioses and I conclude with a synthetic summary of my findings with suggestions
for further research.