Abstract/Summary

Despite their medical implications and widespread distribution, there is limited knowledge of house dust mites. I assessed their biogeographical distribution, examined the genetic system of one of the most common species of house dust mite, Dermatophagoides farinae, and modelled different mating systems of mites, with the aim of improving understanding. This included assembling a database of house dust mite diversity, and identifying the most successful protocols for molecular work, which will save researchers time and provide a solid base for future studies. The creation of a house dust mite fauna database through published resources provided a worldwide distribution of all mites collected from homes. This may prove useful in future, particularly by allergists who are focusing on eradicating these mites for the benefit of human health. In addition, this identified the possibility of a latitudinal diversity gradient in house dust mites. Assessing D. farinae mitochondrial and nuclear genome regions through PCR and sequencing has illustrated dissimilarity between populations. This suggested that D. farinae may have been previously misidentified and the examined populations actually represent more than one species. This gives a basis for further analysis with an increased number of populations from a variety of locations. Finally, modelling and comparing different mating systems which may be found in mites, illustrate that despite the benefits of being haplodiploid, it is difficult to transition to this system from diploidy. This indicates that cytoplasmically inherited maternally-transmitted haplodiploidy is not favoured in diploid populations, forming part of the reason why many species are still in the ancestral diploid state.