Molecular identification of bloodmeals and species composition in Culicoides biting midges

Abstract

Investigations of host preferences in haematophagous insects, including Culicoides biting midges (Diptera: Ceratopogonidae), are critical in order to assess transmission routes of vector-borne diseases. In this study, we collected and morphologically identified 164 blood-engorged Culicoides females caught in both light traps and permanent 12-m high suction traps during 2008-2010 in Sweden. Molecular analysis of the mitochondrial cytochrome c oxidase subunit I (COI) gene in the biting midges was performed to verify species classification, discern phylogenetic relationships and uncover possible cryptic species. Bloodmeal analysis using universal vertebrate cytochrome b primers revealed a clear distinction in host selection between mammalophilic and ornithophilic Culicoides species. Host sequences found matches in horse (n = 59), sheep (n = 39), cattle (n = 26), Eurasian elk (n = 1) and 10 different bird species (n = 18). We identified 15 Culicoides species previously recorded in Scandinavia and four additional species haplotypes that were distinctly different from the described species. All ornithophilic individuals (n = 23) were caught exclusively in the suction traps, as were, interestingly, almost all mammalophilic species (n = 41), indicating that many biting midge species may be able to cover long distances after completing a bloodmeal. These results add new information on the composition of Culicoides species and their host preferences and their potential long-distance dispersal while blood-engorged.

Blood-feeding, susceptibility to infection with Schmallenberg virus and phylogenetics of Culicoides (Diptera: Ceratopogonidae) from the United Kingdom

“…Blood-feeding of Culicoides on pledglets was also demonstrated to underestimate rates of susceptibility to infection, as found previously with BTV [30,31]. The sequencing of the DNA barcode region (658 bp) of the cox1 gene for 67 individuals putatively identified as C. obsoletus from a single site in the UK provides potential evidence of cryptic diversity, however, how this relates to the morphologically cryptic species previously described in the Netherlands, Sweden and Switzerland [27][28][29]59] remains unclear.…”

“…Until recently four species within this subgenus have been identified within this region and are commonly referred to as the Obsoletus group, despite a lack of monophyly: Culicoides obsoletus (Meigen) and Culicoides scoticus Downes & Kettle; Culicoides dewulfi Goetghebuer and Culicoides chiopterus (Meigen) [24][25][26]. Several additional cryptic species have also recently been proposed whose taxonomic status, prevalence, abundance and involvement in transmission of arboviruses remains uncertain [27][28][29]. To date, these cryptic species have not been identified in the UK, despite a study that examined 79 individuals of the subgenus Avaritia using a 472 bp region of the mitochondrial cytochrome c oxidase subunit 1 gene (cox1) across ten geographically disparate sampling points [25].…”

Orientation behaviour of Culicoides obsoletus (Diptera: Ceratopogonidae), a relevant virus vector in northern Europe, toward host-associated odorant cues

“…While some Culicoides species are opportunistic, most Palaearctic species appear to prefer cattle (Bartsch et al, 2009;Lassen et al, 2011;Ninio et al, 2011). Ninio et al (2011) identified the blood of horse, rabbit, pig, sheep and human in the abdomens of blood-fed C. obsoletus females, whereas Pettersson et al (2013) observed the blood of sheep, cattle and horse. This species, thus, seems to feed on a wide range of mammals (Lassen et al, 2012) but to prefer cattle, even when other hosts are present in adjacent areas (Bartsch et al, 2009).…”

“…Several studies have identified the origin of blood present in the abdomen of adult females that have recently fed -which represent a very small proportion of any collection (Service, 1969) -to determine the host range (Blackwell et al, 1994;Bartsch et al, 2009;Garros et al, 2011;Lassen et al, 2011Lassen et al, , 2012Ninio et al, 2011;Calvo et al, 2012;Martinez-de la Puente et al, 2012;Pettersson et al, 2013). Other researchers have collected Culicoides adult females directly from animals used as bait, predominantly with sticky traps or by aspiration (Viennet et al, , 2013Ayllón et al, 2014).…”

A survey of biting midges of the genus Culicoides Latreille, 1809 (Diptera: Ceratopogonidae) in NE Bulgaria, with respect to transmission of avian haemosporidians

“…Several studies have shown that some Culicoides spp. have ornithophilic food preferences (Martínez-De La Puente et al 2011, Pettersson et al 2012, Santiago-Alarcon et al 2012. According to these publications, the Bulgarian list of species includes five species feeding on birds (Appendix 1).…”