Abstract
BackgroundCulicoides biting midges are potential vectors of different pathogens. However, especially for eastern Europe, there is a lack of knowledge on the host-feeding patterns of this vector group. Therefore, this study aimed to identify Culicoides spp. and their vertebrate hosts collected in a wetland ecosystem.MethodsCulicoides spp. were collected weekly from May to August 2017, using Biogents traps with UV light at four sites in the Danube Delta Biosphere Reserve, Romania. Vectors and hosts were identified with a DNA barcoding approach. The mitochondrial cytochrome c oxidase subunit 1 was used to identify Culicoides spp., while vertebrate hosts were determined targeting cytochrome b or 16S rRNA gene fragments. A maximum likelihood phylogenetic tree was constructed to verify the biting midge identity against other conspecific Palaearctic Culicoides species. A set of unfed midges was used for morphological confirmation of species identification using slide-mounted wings.ResultsBarcoding allowed the species identification and detection of corresponding hosts for 1040 (82.3%) of the 1264 analysed specimens. Eight Culicoides spp. were identified with Culicoides griseidorsum, Culicoides puncticollis and Culicoides submaritimus as new species records for Romania. For 39 specimens no similar sequences were found in GenBank. This group of unknown Culicoides showed a divergence of 15.6–16.3% from the closest identified species and clustered in a monophyletic clade, i.e. a novel species or a species without reference sequences in molecular libraries. For all Culicoides spp., nine mammalian and 24 avian species were detected as hosts. With the exception of C. riethi (n = 12), at least one avian host was detected for all Culicoides spp., but this host group only dominated for Culicoides kibunensis and the unknown Culicoides sp.. The most common host group were mammals (n = 993, 87.6% of all identified blood sources) dominated by cattle (n = 817, 70.6%).ConclusionsMost Culicoides spp. showed a broad host-feeding pattern making them potential bridge vectors. At the same time, new records of biting midge species for Romania, as well as a potentially unknown Culicoides species, highlight the lack of knowledge regarding the biting midge species and their genetic diversity in eastern Europe.
Highlights
Culicoides biting midges are potential vectors of different pathogens
Five species were identified for engorged biting midges: C. griseidorsum Kieffer, 1918; C. kibunensis Tokunaga, 1937; C. punctatus; C. riethi Kieffer 1914; and C. submaritimus Tokunaga & Murachi, 1959
Four of the seven detected engorged species were confirmed by morphology: C. griseidorsum; C. kibunensis; C. riethi; and C. punctatus
Summary
Culicoides biting midges are potential vectors of different pathogens. especially for eastern Europe, there is a lack of knowledge on the host-feeding patterns of this vector group. Biting midges of the genus Culicoides Latreille, 1809 (Diptera: Ceratopogonidae) are vectors of a variety of pathogens. These include protozoans [1,2,3], filarial worms [4] and numerous viruses [5]. In Europe, several biting midge species are able to transmit bluetongue virus (BTV), African horse sickness virus and Schmallenberg virus (SBV) [7]. These viruses are responsible for outbreaks of non-contagious diseases in ruminants, causing huge economic losses, e.g. due to restrictions on animal trade [8]. Species-specific information on the distribution of other Culicoides taxa in Romania is missing
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have