A distinct group of north European Aedes vexans as determined by mitochondrial and nuclear markers

Abstract

Abstract. The floodwater mosquito Aedes (Aedimorphus) vexans (Meigen, 1830) (Diptera: Culicidae) is common in several areas of Sweden and is predicted to become more abundant in the wake of expected changes in precipitation and temperature caused by climate change. As well as being a nuisance, Ae. vexans can act as a vector of over 30 viruses. In the event of an outbreak of disease caused by a vector-borne virus, knowledge of the distribution, population structure and intermixing of populations from different locations will help direct resources to target locations to prevent spread of the pathogen. The present study analysed individual Ae. vexans from eight locations throughout Sweden. Based on the mitochondrial cytochrome oxidase I (COI) marker, a subset of the analysed mosquitoes cluster apart from the other samples. Similarly, two nuclear loci were sequenced and the same phylogenetic structure observed. These results indicate that this group represents a reproductively isolated population among Ae. vexans. Comparisons with COI sequences held in the Barcode of Life Database (BoLD) for Ae. vexans from around the world show that specimens collected in Belgium and Estonia group together with the Swedish group, suggesting that this genotype is present throughout northern Europe. These results suggest there is a cryptic taxonomic unit related to Ae. vexans in northern Europe.

Opening the Pandora Box: DNA-barcoding evidence limitations of morphology to identify Spanish mosquitoes

“…Mosquitoes collected from Majorca (Ae. vexans A) would belong to the authors’ Group 2, which has also been reported in Hungary and Sweden (Lilja et al , 2018). Ae.…”

“…The use of nuclear and mitochondrial markers has recently allowed the detection of two different lineages within Ae. vexans (Lilja et al , 2018). Our results are consistent with these findings, with all species delimitation analysis confirming the separation of at least two groups of Ae.…”

Novel Mitochondrial DNA Lineage Found among Ochlerotatus communis (De Geer, 1776) of the Nordic-Baltic Region

“…Whole mosquitoes were used for the DNeasy Blood and Tissue Kit, while three legs from each specimen were taken for extracting DNA with the PrepMan ® Ultra Sample Preparation Reagent. DNeasy Blood and Tissue Kit was used in accordance with the manufacturers manual and the DNA extractions made with PrepMan ® Ultra Sample Preparation Reagent were conducted as specified in previous work [ 26 ].…”

Reproducibility and relevance in insect-arbovirus infection studies

“…As noted above, the increased potential for reproducibility afforded by the use of established insect colony lines may also come at the expense of reflecting the epidemiologically relevant diversity present in field populations. Natural ‘populations’ may be highly genetically heterogeneous, and even represent an assemblage of multiple cryptic species [ 23 , 24 , 25 , 26 , 27 ]. This has been a particular problem for understanding the epidemiology of Culicoides -borne viruses in Northern Europe, where the females of some vector species are morphologically cryptic [ 28 ] (e.g.…”