Molecular identification of bloodmeals from biting midges (Diptera: Ceratopogonidae: Culicoides Latreille) in Denmark

Abstract

Culicoides vectors are critical to the survival and transmission of bluetongue virus as infection only occurs in areas or regions where competent vectors are present. The success of Culicoides biting midges as vectors is mainly related to their vast population sizes and to their means of dispersal. Their choice of host for blood feeding is sparsely described. The aim of the present study was to establish methods for the identification of bloodmeal hosts and determine the identity and diversity of bloodmeals of vertebrate hosts from wild-caught biting midges near livestock farms. The study includes some of the most common and abundant species of biting midges in Denmark: Culicoides obsoletus, Culicoides scoticus, Culicoides pulicaris and Culicoides punctatus. We collected 8,378 biting midges including nine species of Culicoides of which blood-fed specimens were found from six species. We identified 251 blood engorged biting midges, and hosts were identified in 115 of 125 analysed specimens (90%). Cow, roe deer, horse, mallard and wood pigeon were identified as hosts. The most abundant host species was cow, which constituted 73.9% of the total identified bloodmeals, but the common wood pigeon was found with a frequency as high as 18.3%. In conclusion, the molecular methods applied were proven useful in identifying bloodmeal hosts from different Culicoides species. The results indicate that Culicoides species are opportunistic in their choice of bloodmeal host with a preference for cattle when present, which is important to have in mind for epidemiologist when making predictive models. Accordingly, the results of this study will add useful parameters for modelling bluetongue virus transmission and in the development of veterinary contingency plans.

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

“…C. obsoletus also seemed to be attracted to heifer, goat and ewe, as well as birds (Viennet et al, 2013), although this species is considered to be strictly mammalophilic (Lassen et al, 2012). 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.…”

“…In general, many hematophagous species (such as mosquitoes and Culicoides) prefer a specific host on which they will feed (Kettle, 1962;Bartsch et al, 2009;Votypka et al, 2009;Lassen et al, 2012;Viennet et al, 2013), although some species are known to be generalists (Blackwell et al, 1994). Some Culicoides species, however, exhibit opportunistic feeding behaviour with respect to host distribution and density (Kettle, 1977;Garros et al, 2011;Lassen et al, 2011Lassen et al, , 2012Calvo et al, 2012). Visual stimuli and body odour are the two main elements involved in attraction to hosts (Bishop et al, 2008).…”

“…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).…”

Do secretions from the uropygial gland of birds attract biting midges and black flies?

“…The morphological characters are not reliable enough to identify to species level females of the C. obsoletus complex. However, (a) in the Canary Isles, where we conducted the experiment 2, only C. obsoletus and Culicoides analis have been found (Delécolle 2002), (b) only C. obsoletus males have been captured in the study area (authors personal observations) and (c) biting midge species belonging to the "obsoletus complex" including C. obsoletus and Culicoides scoticus, trapped near livestock farms, are capable of feeding on birds such as mallards and common wood pigeons (Lassen et al 2010). Therefore, although the biting midges were not attracted by bird secretions but by the UV light, this is not because pigeons are not potential hosts for these species.…”

Biting midges (Diptera: Ceratopogonidae) in tree hole habitats in Slovakia

“…In general, however, its development sites still remain poorly documented (Szadziewski 1985). Females of C. obsoletus are known to attack livestock and humans (Szadziewski 1985), but they can also readily feed on birds (Lassen et al 2011). This very common and widely distributed species is susceptible to infection with BTV-8 and BTV-9, therefore it is considered to be a probable vector of the bluetongue virus in Europe (Carpenter et al 2008).…”