| Culicoides | |
|---|---|
 | |
| Culicoides sonorensis after blood meal | |
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Diptera |
| Family: | Ceratopogonidae |
| Subfamily: | Ceratopogoninae |
| Tribe: | Culicoidini |
| Genus: | Culicoides Latreille, 1809 |
| Subgenera | |
Numerous, see text | |
Culicoides is agenus ofbiting midges in thefamilyCeratopogonidae. There are over 1000 species in the genus,[1][2] which is divided into many subgenera. Severalspecies are known to bevectors of various diseases andparasites which can affect animals. The genus has a long fossil record, with earliest known fossils being fromBurmese amber, around 99 million years old.[3]
Thesystematics andtaxonomy of this genus are confused. A large number of species are of unknown relation to those that have been assigned tosubgenera already. Furthermore, many subgenera are sometimes elevated to full genus status, or additional genera (such asParadasyhelea) are included as subgenera herein.
A widely cited, periodically updated, subgeneric classification of species ofCulicoides begins with the warning that the traditional approach to classification of species in this genus has led to "phylogenetic chaos". Some of the specific consequences are mentioned, as well as recommendations for future work.[4] A molecular phylogeny based on 42 species from 3 continents was proposed in 2017.[5] In this work, the authors found that the subgeneraMonoculicoides,Culicoides,Haematomyidium,Hoffmania,Remmia andAvaritia (including the main vectors ofbluetongue virus disease) were monophyletic, whereas the subgenusOecacta was paraphyletic. The study validated the subgenusRemmia (= Schultzei group) as a valid subgenus, outside of the subgenusOecacta. The authors also considered that in Europe,Culicoides obsoletus,Culicoides scoticus andCulicoides chiopterus should be part of theObsoletus complex whereasCulicoides dewulfi should be excluded from this complex. The authors concluded that the currentCulicoides classification needed to be revisited with modern tools.[5]
_and_Midge_(Culicoides_impunctatus)_biting_human_(me).jpg)
Speciesincertae sedis include:
Adults are small dark insects about 1–3 mm long. The antennae are long (15 segments) densely haired in the males and less hairy in females. Thethorax is hooped and carries a pair of broad mottled wings. Only the first two longitudinal veins are distinct. Midges are morphologically distinct from mosquitoes, lacking a proboscis, limiting their ability to bite through clothing.
Both males and females feed on nectar, however only the females take a blood meal, which is needed for the maturation of fertilized eggs.[2] Females typically bite at dusk or dawn often in dense swarms and usually in the vicinity of water, marshes or rotting vegetation.
Females lay their eggsen masse in a range of habitats ranging from water vegetation, slow running streams, damp soil or on manure heaps. These hatch into tiny smooth white larvae with four pairs of anal gills. Pupae consist of a fusedcephalothorax with slender respiratory trumpets and a segmented abdomen.Adults emerge through a straight slit after 3–7 days.
Species ofCulicoides feed on a variety of mammal hosts, including humans.[6] The bite ofCulicoides is felt as a sharp prick and is often followed by irritating lumps that may disappear in a few hours or last for days.
VariousCulicoides species have been shown to bevectors for the following viruses and conditions:Mansonella spp. (M. ozzardi,M. perstans,M. streptocerca),Onchocerca gibsoni andO. cervicalis,Leucocytozoon,Plasmodium agamae,bluetongue virus,Oropouche virus,Schmallenberg virus,African horse sickness,bovine ephemeral fever (C. osystoma andC. nipponesis),Akabane virus,Queensland itch andepizootic hemorrhagic disease.[7] A typical cycle of transmission of a virus byCulicoides is illustrated in the articleParasitic flies of domestic animals. Three species ofCulicoides are established vectors for three species ofApicomplexan parasites of the genusHepatocystis.
In 2006,bluetongue virus was first recorded in Northern Europe. In 2007 and 2008, there were huge outbreaks, going as far as Norway, but in 2009 the outbreak was smaller. The main vector of the virus in Southern Europe does not live in Northern Europe, so other species have been screened. Species belonging to theCulicoides obsoletus complex and theCulicoides pulicaris complex have been found capable of bluetongue transmission.[8]
