Latitudinal diversity of biting midge species within the Obsoletus group across three habitats in Europe

Abstract

Culicoides species from the Obsoletus group are important vectors of bluetongue and Schmallenberg virus. This group consists of several species that cannot easily be identified using morphological characteristics. Therefore, limited information is available about their distribution and habitat preferences. In this study, we aimed to elucidate the species composition of the Obsoletus group in three habitat types at climatically different latitudes across Europe. Traps were placed in three habitat types in three countries at different latitudes. After DNA extraction, biting midges were identified using PCR and gel electrophoresis. Extraction of DNA using Chelex proved to be a cost and time efficient method for species identification. A latitudinal effect on the relative abundance of species from the Obsoletus group was found. Species composition was unique for most country‐habitat combinations. The majority of biting midges were either C. obsoletus s.s. or C. scoticus, and both species were found at all latitudes and habitats. Their wide distribution and their high abundance at livestock farms make these species likely candidates for rapid farm‐to‐farm transmission of pathogens throughout Europe. Our results emphasize the need to differentiate Obsoletus group species to better understand their ecology and contribution to pathogen transmission.

The tree that hides the forest: cryptic diversity and phylogenetic relationships in the Palaearctic vector Obsoletus/Scoticus Complex (Diptera: Ceratopogonidae) at the European level

“…Species assignment at the European scale showed variation in the distribution of the cryptic diversity of Obsoletus/Scoticus Complex. This result confirmed a previous study by Möhlmann et al [49], who found a strong latitudinal effect on the relative abundance of species of the Obsoletus/Scoticus Complex. However, the previous study was carried out with few individuals from a relatively small number of countries and sampling sites [49].…”

“…This result confirmed a previous study by Möhlmann et al [49], who found a strong latitudinal effect on the relative abundance of species of the Obsoletus/Scoticus Complex. However, the previous study was carried out with few individuals from a relatively small number of countries and sampling sites [49]. This contrasts with our study, the first to be conducted at a European scale with a large data set sufficient to provide a more precise idea of the cryptic diversity within the Obsoletus/Scoticus Complex.…”

Species Identity, Life History, and Geographic Distance Influence Gut Bacterial Communities in Lab-Reared and European Field-Collected Culicoides Biting midges

“…After identification of the species in the Obsoletus group, five abdomens per species were pooled in a 2-ml screw-cap microtube (Sarstedt) with a 4-mm borosilicate glass bead (Sigma-Aldrich). As expected, the four species of the Obsoletus group were not present in all the studied countries [38]. Therefore, a total of 20 pools were made for Sweden (1 × C. dewulfi, 5 × C. obsoletus s.s., 14 × C. scoticus), 37 pools for The Netherlands (3 × C. chiopterus, 12 × C. dewulfi, 11 × C. obsoletus s.s., 11 × C. scoticus) and 18 pools for Italy (9 × C. obsoletus s.s., 9 × C. scoticus) (Table 1).…”

“…For molecular identification, DNA was extracted using a Chelex-based extraction method [ 37 , 38 ]. First, 30 µl of 5% Chelex® 100 resin (143–2832 BioRad) in ultrapure water was added to each sample in the 96-well plate.…”