Culicoides

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Culicoides
BitingMidge.jpg
Culicoides sonorensis after blood meal
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Diptera
Family: Ceratopogonidae
Subfamily: Ceratopogoninae
Tribe: Culicoidini
Genus: Culicoides
Latreille, 1809
Subgenera

Numerous, see text

Culicoides is a genus of biting midges in the family Ceratopogonidae. There are over 1000 species in the genus,[1][2] which is divided into many subgenera. Several species are known to be vectors of various diseases and parasites which can affect animals.

Notable taxa[edit]

The systematics and taxonomy of this genus are confused. A large number of species are of unknown relations to those that have been assigned to subgenera already. Furthermore, many subgenera are sometimes elevated to full genus status, or additional genera (such as Paradasyhelea) are included as subgenera herein.

A widely cited, periodically updated, subgeneric classification of species of Culicoides 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.[3] A molecular phylogeny based on 42 species from 3 continents was proposed in 2017.[4] In this work, the authors found that he subgenera Monoculicoides, Culicoides, Haematomyidium, Hoffmania, Remmia and Avaritia (including the main vectors of bluetongue virus disease) were monophyletic, whereas the subgenus Oecacta was paraphyletic. The study validated the subgenus Remmia (= Schultzei group) as a valid subgenus, outside of the subgenus Oecacta. The authors also considered that in Europe, Culicoides obsoletus, Culicoides scoticus and Culicoides chiopterus should be part of the Obsoletus complex whereas Culicoides dewulfi should be excluded from this complex. The authors concluded that the current Culicoides classification needed to be revisited with modern tools.[4]

  • Subgenus Avaritia
Culicoides brevitarsis

Species incertae sedis include:

Taxonomy[edit]

Wing pattern of 12 species of Culicoides

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. The Thorax is hooped and carries a pair of broad mottled wings. Only the first two longitudinal veins are distinct.

Biological habits: Both males and females feed on nectar, however only the females feed on blood, 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.

Life cycle of Culicoides: Females lay their eggs en masse in a range of habitats ranging from water vegetation, slow running streams, damp soil or manure heaps. These hatch into tiny smooth white larvae with four pairs of anal gills. Pupae consist of a fused cephalothorax with slender respiratory trumpets and a segmented abdomen. Adults emerge through a straight slit after 3–7 days.

The bite of Culicoides is felt as a sharp prick and is often followed by irritating lumps that may disappear in a few hours or last for days.

Culicoides as a vector[edit]

Various Culicoides species have been shown to be vectors for the following viruses and conditions: Mansonella spp. (M. ozzardi, M. perstans, M. streptocerca), Onchocerca gibsoni and O. cervicalis, Leucocytozoon, Plasmodium agamae, bluetongue virus, Schmallenberg virus, African horse sickness, bovine ephemeral fever (C. osystoma and C. nipponesis), Akabane virus, Queensland itch and Epizootic Hemorrhagic Disease.[5] A typical cycle of transmission of a virus by Culicoides is illustrated in the article Parasitic flies of domestic animals.

Bluetongue vectors in Northern europe[edit]

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 the Culicoides obsoletus complex and the Culicoides pulicaris complex have been found capable of bluetongue transmission.[6]

References[edit]

  1. ^ Meiswinkel, R., et al. (2004). The taxonomy of Culicoides vector complexes–unfinished business. Vet Ital 40(3), 151-59.
  2. ^ a b Connelly, C. R. Biting midges: Culicoides spp. Featured Creatures, Entomology and Nematology Department, University of Florida IFAS. August 2013 Edition.
  3. ^ Borkent, Art (2016). "The Subgeneric Classification of Species of Culicoides" (PDF). Illinois Natural History Survey. University of Illinois at Urbana-Champaign. Retrieved 16 January 2017. 
  4. ^ a b Augot, Denis; Mathieu, Bruno; Hadj-Henni, Leila; Barriel, Véronique; Zapata Mena, Sonia; Smolis, Sylvia; Slama, Darine; Randrianambinintsoa, Fano José; Trueba, Gabriel; Kaltenbach, Matthieu; Rahola, Nil; Depaquit, Jérôme (2017). "Molecular phylogeny of 42 species of Culicoides (Diptera, Ceratopogonidae) from three continents". Parasite. 24: 23. doi:10.1051/parasite/2017020. ISSN 1776-1042.  open access publication – free to read
  5. ^ Purse, B.V.; Carpenter, S.; Venter, G.J.; Bellis, G.; Mullens, B.A. (2015). "Bionomics of Temperate and Tropical Culicoides Midges: Knowledge Gaps and Consequences for Transmission of Culicoides-Borne Viruses". Annual Review of Entomology. 60 (1): 373–392. doi:10.1146/annurev-ento-010814-020614. ISSN 0066-4170. 
  6. ^ Bessell, Paul R.; Searle, Kate R.; Auty, Harriet K.; Handel, Ian G.; Purse, Bethan V.; Bronsvoort, B. Mark de C. (2016). "Assessing the potential for Bluetongue virus 8 to spread and vaccination strategies in Scotland". Scientific Reports. 6: 38940. doi:10.1038/srep38940. ISSN 2045-2322.