Culicoides scoticus Downes and Kettle, 1952

General information for the taxon Biogeographic region where the taxon is recorded : Palaearctic

Culicoides obsoletus and C. scoticus are known to be sibling species meaning that females cannot be distinguished based on morphological characters. However, males can be discriminated according to genitalia characteristics.

female diagnose as in C. obsoletus . Wing with pale spots relatively marked. Pale spots distally present in r5, m1, m2 and m4 cells. Presence of two functional spermathecae with subequal size and 1 rudimentary spermatheca. Presence of sclerotized ring

male diagnose:
Hypopygium without postlateral processes.
Aedeagus characterized by shape of horseshoe with a well marked expansion apically (less marked and thiner for C. obsoletus). Ninth sternite franckly divided in two, triangular-shaped.

C. obsoletus and C. scoticus are found in association with various breeds of livestock. Both species are widely distributed in Western Europe and usually abundant. C. obsoletus midges have been found emerging from manure left outside the farm buildings, but also from indoor samples. Zimmer et al (2010) found that dried dung adhering to walls inside animal enclosures and used animal litter was a breeding site for the C. obsoletus/scoticus complex. They also observed that C. obsoletus/scoticus complex midges were more prevalent in soil samples with a high carbon:nitrogen (C:N) index; this index indicates the amount of organic matter in soil. Viennet et al (2012) did not identified preferential landing sites for C. obsoletus (horse used as baits) whereas Townley et al. (1984) found most of C. obsoletus landing and feeding on upper parts of horse, Overgaard Nielsen (1971) on belly of heifers and Viennet et al. (2011) on lower parts of sheep. Culicoides obsoletus is able to enter into buildings. The outdoor/indoor ratio of C. obsoletus abundance was higher in summer than in spring and autumn, and was dependent on the building opening. Culicoides obsoletus was active before sunset in spring and autumn and after sunset in summer.

Implications as vector species
Culicoides obsoletus plays a significant role in the spread of BTV. Both sibling species are abundant in BTV-infected areas and virus has been isolated from specimens belonging to these two groups during outbreaks in Italy and detected in these species using real-time polymerase chain reaction (PCR) in central Western Europe. Furthermore, in laboratory studies, the Obsoletus group has proven orally susceptible for BTV 8 and 9 (Carpenter et al. 2008).

  family Ceratopogonidae
Important bibliographic reference(s)
Specimen(s) present in collection (1)
AVAbase ID Country of collection Voucher Sequence(s) Status Sample(s) Picture(s) Number
AVA7 France In collection Single individual

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Distribution map for specimen(s) present in collection