{{Short description|Species of fly}} {{Speciesbox |image = Tabanidae - Haematopota pluvialis.-2.JPG |image_caption = |genus = Haematopota |species = pluvialis | display_parents = 3 |authority = (Linnaeus, 1758) |synonyms = }}

The '''common horse fly''' ('''''Haematopota pluvialis'''''), also known as the '''notch-horned cleg fly''', or simply '''cleg''' in Scotland and northern parts of Ireland, is a fly species belonging to the family Tabanidae subfamily Tabaninae.<ref>[https://www.biolib.cz/en/taxon/id124056/ Biolib]</ref><ref name="Stubbs"> {{cite book |last=Stubbs |first=Alan E. |author2=Drake, Martin |title=British Soldierflies and their allies: A Field Guide to the Larger British Brachycera |type=Print |date=2001 |publisher=British Entomological and Natural History Society |location=London |isbn=1-899935-04-5 |pages=528 pages }}</ref><ref name="Chvála">{{cite book |last1=Chvála |first1=Milan |last2=Lyneborg |first2=Leif |last3=Moucha |first3=Josef |title=The Horse Flies of Europe (Diptera, Tabanidae) |date=1972 |publisher=Entomological Society of Copenhagen |location=Copenhagen |isbn=978-09-00-84857-5 |pages=598pp, 164figs}}</ref>

==Distribution and habitat== This species is present in most of Europe, in the Near East, and in the eastern Palearctic realm.<ref>[https://web.archive.org/web/20121019094254/http://www.faunaeur.org/full_results.php?id=66335 Fauna europaea]</ref> It mainly lies in heath and moorland, and in spruce forest edge.<ref name=CC/>

==Description== thumb|240px|left|Female of ''Haematopota pluvialis'' Common horse flies can reach a length of {{convert|5|-|11.5|mm}}, with a wingspan of 8–10&nbsp;mm.<ref name=CC>[http://www.commanster.eu/commanster/Insects/Flies/SpFlies/Haematopota.pluvialis.html Commanster]</ref> This species has large compound eyes necessary for locating its prey. They are hairy and brightly colored, with stripes extended over most of the eye. In males, the eyes touch at the centre of the frons and the colored stripes are restricted to the lower part.<ref name=AA/><ref name=BB>[http://www.naturespot.org.uk/species/notch-horned-cleg Nature Spot]</ref> [[File:Haematopota pluvialis (female) - 2012-07-04.ogv|thumb|thumbtime=0:32|Female in a wet meadow]] The first antennal segment is quite bulbous and has a strong sub-apical notch in the female. The thorax is grey, with black longitudinal stripes. The abdomen shows a dark background with a series of lateral pale spots and clearer bands at the end of each black segment. Also the wings have a distinctive pattern, being dark mottled by several clear spots. The legs are black, with yellowish-brown rings.<ref name=AA>[http://influentialpoints.com/Gallery/Haematopota_pluvialis_Common_or_Notch-horned_cleg.htm Influential Points]</ref><ref>{{cite book|url=https://books.google.com/books?id=jRI1AAAAMAAJ&dq=Haematopota+pluvialis&pg=PA35|title=Illustrations of British blood-sucking flies|publisher=British Museum of Natural History|author=Ernest Edward Austen|page=95|year=1906|author-link=Ernest Edward Austen}}</ref>

This species is similar to the also common ''Haematopota crassicornis'', but differs from that species in the orange third antennal segment, in the presence of the sub-apical notch and in the overall brown colouration compared to the often grey tinge of ''crassicornis''.<ref name=AA/><ref name=BB/>

==Biology== These horse flies can be encountered during the daylight hours from late May through late October.<ref name=CC/> The males are harmless and feed on nectar,<ref name=BB/> while the females feed on mammal blood (hematophagy) (hence the Latin name ''Haematopota pluvialis'', literally meaning 'blooddrinker of the rains'), mainly cattle and horses, needing blood for developing eggs. When they bite they inject fluids inhibiting the coagulation of blood, which flows out in such a way that allows the horsefly to lap it. They are also able to bite humans painfully. Females lay their eggs at the base of grass-stems or on the surface of moist soil.

==Gallery== <gallery widths="240" heights="180"> File:Haematopota pluvialis (Diptera sp.), Giethoorn, the Netherlands.jpg|Female File:Haematopota pluvialis01.jpg|Male, with its characteristic eyes File: Tabanidae - Haematopota pluvialis-001.JPG|The separated female eyes File:Haematopota.pluvialis.wing.detail.jpg|Wing detail </gallery>

==Bibliography== * Brightwell, R. & Dransfield, R.D. (2014). [http://influentialpoints.com/pdfs/A_preliminary_survey_of_tabanidae_horseflies_in_southern_England_2014.pdf Survey of Tabanidae (horseflies) in southern England 2014. A preliminary survey of tabanids using odour-baited NG2F traps.] 14 pp. * Burgess, N.R.H. et al. (1978). The immature stages of the common cleg Haematopota pluvialis L. (Diptera: Tabanidae). J. roy. Army med. Cps. 124, 27-30. * Cameron, A.E. (1930). Oviposition of Haematopota pluvialis Linne. Nature 126, 601-602. * Grayson, A. (2001). Notes on the behaviour of males of Haematopota crassicornis Wahlberg and Haematopota pluvialis (Linnaeus). Larger Brachycera Recording Scheme Newsletter 19. * Kniepert, F.W. (1980). [https://link.springer.com/article/10.1007/BF00346976#page-1 Blood-feeding and nectar-feeding in adult Tabanidae (Diptera).] Oecologia 46, 125-129. * Krčmar, S. (2004). Ecological notes on Tabanus bromius L., and Haematopota pluvialis (L.), (Diptera: Tabanidae) of some flood areas in Croatian sections of the river Danube. Journal of Vector Ecology 29(2), 376-378. * Krčmar, S. et al. (2006). [http://www.sove.org/Journal/Entries/2006/12/1_Volume_31,_Number_2_files/7%20Krcmar%2006-29.pdf Response of Tabanidae (Diptera) to different natural attractants.] Journal of Vector Ecology 31(2), 262-265. Full text * Liebisch, A.(1987). Vector Biology of Flies on Grazing Cattle in Germany. Veterinary Medicine and Animal Science 45, 109-115. * Titchener, R.N. et al. (1981). [https://www.ncbi.nlm.nih.gov/pubmed/7244374 Flies associated with cattle in south west Scotland during the summer months.] Researches in Veterinary Science 30 (1), 109-113. *Ross, H.C.G. 1978 - A note on the hovering behaviour of Haematopota pluvialis (Linne, 1758) (Diptera:Tabanidae) Entomologist’s Gazttte 28:267-268 *Stone, A.L. and Philip, B., 1974 - The Oriental Species of the Tribe Haematopotini (Diptera, Tabanidae), United States Department of Agriculture, Agriculture Research Service - Technical Bulletin, 1489 - Washington D.C.

==References== {{Reflist}}

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Category:Tabanidae Category:Insects described in 1758 Category:Flies of Europe Category:Articles containing video clips Category:Animal taxa named by Carl Linnaeus