Chiang Mai Journal of Science

Darwin’s classic reference to the “tangled bank” acknowledges the living biodiversity. Traditionally, biodiversity assessment has been the realm of  the classical taxonomist. However, times have changed swiftly and now biodiversity may be assessed by high throughput sequencing of  short regions of  DNA. Commonly, this is called DNA “barcoding”.  In this study, we investigate the genetic diversity within and between four morphological mosquito species that are vectors of  medically important viral pathogens.  We obtained 627 bp of  sequence information from the N-terminus of  the mitochondrially encoded cytochrome  c oxidase I (COI) gene from 12 Aedes vigilax and 10 Ae. camptorhynchus representing five localities in Australia. We also downloaded GenBank COI sequence data from 18 Ae. albopictus and 14 Ae. aegypti. Maximum likelihood phylogenetic analyses recovered the four distinct morphological species, as well as a distinct lineage within what is currently described as Ae. vigilax. We termed this lineage ‘A’. Intra- and interspecific variation quantified for Ae. vigilax and Ae. vigilax lineage ‘A’ suggest that this morphospecies may include distinct genetic or cryptic species. Ae. aegypti also had high intraspecific variation, however, we concluded that this is most likely due to the large effective population size of  this species and its broad distribution through the tropics. Phylogenetic analyses and analyses of  genetic diversity at COI suggests that Ae. camptorhynchus and Ae. albopictus are robust species. The results of  this study highlight the efficiency, utility and ease of  barcoding.  The study also documents specific limitations including the importance of taxon sampling and the necessity for this tool to be used in conjunction with additional taxonomic techniques, ecological studies and physiological data.