Hyalomma marginatum

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Hyalomma marginatum
Hyalomma marginatum

Hyalomma marginatum

Systematics
Subclass : Mites (acari)
Superordinate : Parasitiformes
Order : Ticks (ixodida)
Family : Shield ticks (ixodidae)
Genre : Hyalomma
Type : Hyalomma marginatum
Scientific name
Hyalomma marginatum
CL Koch , 1844

Hyalomma marginatum is a species of tick with distribution in subtropical regions of the Old World. The sexanimals( imagines ) suck blood from a variety of mammal species, preferably ungulates, but occasionally also humans. Immature occur in a wide variety of vertebrates, including migratory birds. The species has medical significance as a vector of Crimean-Congo fever and spotted fever . Their detection in Germany in the very warm summer of 2018 has therefore attracted a great deal of attention, as it is feared that it will spread to Central Europe.

features

As is typical for the genus, it is a relatively large tick with a body length of about 5 to 6 millimeters, with the back shield (scutum or conscutum) covering the entire trunk section when not completely soaked. It is noticeably larger than the most common type of common wood tick in Europe . The legs are lighter than the shield and usually noticeably curled. The species is difficult to distinguish from other members of the genus and, as a rule, can only be distinguished when it is sexually mature. Immature stages (larvae and nymphs) may have species-specific characteristics, but are so similar to the related species that they are usually considered morphologically indeterminate.

Determination is possible on the basis of the following characteristics: The sign is colored brown, without a pattern of irregularly converging white spots. The surface is rough and dull, with an even, deep puncture made up of large, closely spaced points. The hips (coxa, the first leg link) of the first pair of legs are deeply split, with two unevenly shaped spurs (one conical and pointed, the other flattened) that reach about the same length. In the male, the longitudinal furrows on the side of the upper side of the shield are clear and of medium length, they reach about a third of the length of the shield. At the rear end of the shield, a small, lighter-colored recess in the shield edge (called Parma) is not pronounced. It is difficult to differentiate from the closely related Hyalomma rufipes (which has long been considered a subspecies of this species): the puncture on the upper side is somewhat finer, on the underside the area around the stigmas is sparse, not dense, hairy, the stigma plate is at the back pulled out slightly narrower projection.

Biology and ecology

Hyalomma marginatum is a two-host tick. Larvae and nymphs (the second immature stage of development) develop sequentially on a host . The soaked nymphs eventually fall off. They then wait in the habitat for the second host, on which the development to the imago and the mating take place. The species has only one generation per year in its natural habitat. The ticks are only active in spring and summer when the ambient temperature is warm. Larvae are observed in June and July, nymphs from July. The adults hibernate, are active from March and reach their maximum activity in May. However, individual animals are active until late summer or even early autumn. The species actively searches for its hosts. So it is not a lurker like the common wood tuck, but actively moves through the habitat in search of hosts. The host search is presumably based primarily on chemical sensory stimuli, but mechanical and optical stimuli have also been found in related species.

Hosts of the immature stages are small, ground-living mammals, especially rabbits and insect-eaters , and ground-living bird species, including many songbirds. The hosts of the adult animals are large mammals, especially wild and domesticated ungulates , especially cattle . Humans, as false hosts, are also stung relatively often.

distribution

Evidence of the species (in the narrower sense) is available from North Africa, the European Mediterranean area and the west and center of Asia, east to the south of Russia, Pakistan and Turkmenistan. Evidence from South Africa relates to other species (former subspecies that are now considered separate). Due to the difficult taxonomy of the species group, older records in particular are difficult to assign to a species. The species is widespread in southern Europe. It occurs in the Balkans to the south of Romania, Bosnia and Albania. Populations in the western Mediterranean (Italy, Spain) are separated from this range. Direct evidence of reproductive populations from the south of France has long been pending, but is now considered highly likely. Individual finds on cattle in Hungary, on the other hand, relate to the closely related Hyalomma rufipes , which is now regarded as a separate species .

The species was transported very far through human transport and the occurrence of immatures on migratory birds, so that individual finds are available almost worldwide. In this way, individuals could be detected in Brazil without them being able to establish themselves there.

Spread to the north

An area expansion of this type to the north has been observed for some time. This causes concern among epidemiologists because of their importance as a disease vector . The species has become extremely common in Turkey, where it used to be quite rare, and is now one of the most common types of ticks. 85 percent of the ticks found on cattle in the country now belong to this species.

Individuals of the species (or at least the species group) have been found occasionally on migratory birds in Germany for many years. In the summer of 2018, ticks of the species could now also be detected on livestock (horses and sheep) in Germany for the first time. Finds are from very different regions ( Osnabrück area , Hanover , Wetterau in Hesse ). In December 2018 a specimen was found on a horse farm in Bokelholm, Schleswig-Holstein. Establishment in Germany has not yet been proven, but it is feared for the future. (However, the species had already been found in 2017, in a garden, on a trouser leg in Tübingen .) Contrary to the representation in the media, it is not a "tropical" species, it does not occur in the tropics. In June 2019 it was shown for the first time in Upper Austria that a specimen overwintered.

According to model estimates, under realistic climate models, a spread of the species in southern Germany to the southern Netherlands appears realistic.

In Austria, a sexually mature animal infected with the Rickettsia aeschlimannii bacterium (a spotted fever pathogen, symptoms similar to Boutonneuse fever ) was first detected in the Melk area in 2018 . The tick with the same pathogen was previously genetically detected on a reed warbler in Zerbst (Saxony-Anhalt), the northernmost point of discovery to date.

Phylogeny and Taxonomy

The species belongs within the genus to the subgenus Euhyalomma , in which it forms the marginatum species group with a number of relatives . It is a taxonomically difficult aggregate of similar species, most of which were previously regarded as subspecies of H. marginatum . The monophyly of the genus and the subgenus were confirmed by molecular methods. The sister species is therefore Hyalomma turanicum , and Hyalomma rufipes is also closely related.

Synonyms are, among others, Hyalomma plumbeum Panzer, 1795 and Hyalomma savignyi (Gervais, 1844).

Medical importance

Like many species of the genus Hyalomma , Hyalomma marginatum transmits the virus disease Crimean-Congo fever . The species is considered the main vector of the disease in southern Europe, the Middle East, and Central Asia.

Web links

Commons : Hyalomma marginatum  - collection of images, videos and audio files

Individual evidence

  1. ↑ Sobhy Abdel-Shafy, Amira H. El Namaky, Nesreen AT Allam, Seham Hendawy (2016): Scanning electron microscopy and morphometrics of nymph and larva of the tick Hyalomma rufipes Koch, 1844 (Acari: Ixodidae). Journal of Parasitic Diseases 40 (1): 1-10. doi: 10.1007 / s12639-014-0450-6
  2. ^ A b c d e Agustín Estrada-Peña, Andrei Daniel Mihalca, Trevor N. Petney: Ticks of Europe and North Africa: A Guide to Species Identification. Springer Verlag Berlin etc. 2018, ISBN 978-3-319-63760-0 .
  3. ↑ Asadollah Hosseini-Chegeni, Reza Hosseini, Majid Tavakoli, Zakiyeh Telmadarraiy, Mohammad Abdigoudarzi: The Iranian Hyalomma (Acari: Ixodidae) with a key to the identification of male species. Persian Journal of Acarology 2 (3): 503-529.
  4. ^ AD Mihalca, MO Dumitrache, C. Magdaş, CM Gherman, C. Domşa, V. Mircean, IV Ghira, V. Pocora, DT Ionescu, S. Sikó Barabási, V. Cozma, AD Sándor (2012): Synopsis of the hard ticks (Acari: Ixodidae) of Romania with update on host associations and geographical distribution. Experimental and Applied Acarology 58: 183-206. doi: 10.1007 / s10493-012-9566-5
  5. ↑ Laurence Vial et al. (2012): Strong evidence for the presence of the tick Hyalomma marginatum Koch, 1844 in southern continental France. Ticks and Tick-borne Diseases 7 (6): 1162-1167. doi: 10.1016 / j.ttbdis.2016.08.002
  6. ↑ Sándor Hornok & Gábor Horváth (2012): First report of adult Hyalomma marginatum rufipes (vector of Crimean-Congo haemorrhagic fever virus) on cattle under a continental climate in Hungary. Parasites & Vectors 5: 170. doi: 10.1186 / 1756-3305-5-170
  7. ↑ Filipe Dantas-Torres, Valeria Castilla-Onofrio, Darci Moraes Barros-Battesti (2009): The ticks (Acari: Ixodida: Argasidae, Ixodidae) of Brazil. Systematic & Applied Acarology 14: 30-46.
  8. ↑ Hyalomma marginatum - Factsheet for experts . ECDC European Center for Disease Prevention and Control.
  9. ↑ Trevor N. Petney, Miriam P. Pfäffle, Jasmin D. Skuballa (2012): An annotated checklist of the ticks (Acari: Ixodida) of Germany. Systematic & Applied Acarology 17 (2): 115-170.
  10. ↑ Miroslav Capek, Ivan Literak, Elena Kocian, Oldrich Sychr, Tomas Najer, Alfred Trnka, Pavel Kverek (2014): Ticks of the Hyalomma marginatum complex transported by migratory birds into Central Europe. Ticks and Tick-borne Diseases 5 (5): 489-493. doi: 10.1016 / j.ttbdis.2014.03.002
  11. ↑ Dangerous tick appeared in Schleswig-Holstein. ndr.de, January 29, 2019
  12. ↑ Tropical tick species: Several finds in Germany worry experts Press release, University of Hohenheim, August 14, 2018.
  13. ↑ Alarmed experts: Tropical tick reaches Germany tagesschau.de, as of August 14, 2018, 5:33 p.m.
  14. ↑ Rainer Oehme, Malena Bestehorn, Silke Wölfel, Lidia Chitimia-Dobler (2017): Hyalomma marginatum in Tübingen, Germany. Systematic & Applied Acarology 22 (1): 1-6. doi: 10.11158 / saa.22.1.1
  15. ↑ ORF at / Agencies red: Science: Giant tick overwintered in Austria for the first time. June 12, 2019, accessed June 12, 2019 .
  16. ↑ Agustin Estrada-Peña, Nely Sánchez, Adrián Estrada-Sánchez (2012): An Assessment of the Distribution and Spread of the Tick Hyalomma marginatum in the Western Palearctic Under Different Climate Scenarios. Vector-Borne and Zoonotic Diseases 12 (9): 758-768. doi: 10.1089 / vbz.2011.0771
  17. ↑ Subtropical ticks reached Austria on ORF on December 7, 2018, accessed on December 9, 2018.
  18. ↑ https://www.vetmeduni.ac.at/de/infoservice/presseinformationen/presseinformationen-2018/hyalomma-marginatum-fund/
  19. ↑ Leonid Rumer, Elmara Graser, Timo Hillebrand, Thomas Talaska, Hans Dautel, Oleg Mediannikov, Panchali Roy-Chowdhury, Olga Sheshukova, Oliver Donoso Mantke, Matthias Niederig (2011): Rickettsia aeschlimannii in Hyalomma marginatum Ticks, Germany. Emerging Infectious Diseases 17 (2): 325-326. doi: 10.3201 / eid1702.100308
  20. ↑ Arthur F. Sands, Dmitry A. Apanaskevich, Sonja Matthee, Ivan G. Horak, Alan Harrison, Shahid Karim, Mohammad K. Mohammad, Kosta Y. Mumcuoglu, Rupika S. Rajakaruna, Maria M. Santos-Silva, Conrad A. Matthee (2017): Effects of tectonics and large scale climatic changes on the evolutionary history of Hyalomma ticks. Molecular Phylogenetics and Evolution 114: 153-165. doi: 10.1016 / j.ympev.2017.06.002