Ixodes ricinus

File:Ixodes cf ricinus - part 1 - 2012-05-21.ogv ricinus filmed in a forest near Marburg, Hesse, Germany]]

In common with other species of Ixodes, I. ricinus has no eyes and is not ornate; it has no festoons (wrinkles along the posterior margin). The palpi are longer than they are wide, and an anal groove is above the anus. {{cite journal |author=Walker, M.D. |year=2018 |title=The Biology and Ecology of the Sheep Tick Ixodes ricinus |journal=Antenna: Royal Entomological Society |volume=42 |issue=2 |pages=61–65 |url=https://www.academia.edu/36581467 |format=PDF}}

It has a hard dorsal shield which covers the entire opisthosoma (abdomen), but only part of it in females and nymphs.{{cite book |author=Jaime Samour |year=2000 |title=Avian medicine |publisher=Elsevier Health Sciences |isbn=978-0-7234-2960-9 |chapter-url=https://books.google.com/books?id=6NwOiVu288UC&pg=PA223 |pages=223–224 |chapter=Ticks}} I. ricinus is the largest of the three common species of Ixodes in the British Isles (the other two being I. canisuga, the British dog tick, and I. trianguliceps, the vole tick). Adult males are {{convert|2.4|-|2.8|mm|2|abbr=on}} long, and unfed nymphs are {{convert|1.3|-|1.5|mm|2|abbr=on}} long; females are {{convert|3.0|-|3.6|mm|2|abbr=on}} long before feeding and {{convert|11|mm|2|abbr=on}} long when engorged.{{cite web |url=http://webpages.lincoln.ac.uk/fruedisueli/FR-webpages/parasitology/Ticks/TIK/tick-key/background_ixodes.htm |title=Background information: Ixodes ricinus |author=Frank L. Ruedisueli & Brigitte Manship |publisher=University of Lincoln |access-date=July 22, 2010 |archive-date=April 2, 2015 |archive-url=https://web.archive.org/web/20150402130910/http://webpages.lincoln.ac.uk/fruedisueli/FR-webpages/parasitology/Ticks/TIK/tick-key/background_ixodes.htm |url-status=dead }}

Ixodes ricinus is found across Europe and into neighbouring parts of North Africa and the Middle East, extending as far north as Iceland and as far east as parts of Russia. Its northern limit seems to be determined by environmental factors, including temperature, since a series of mild winters in Scandinavia coincided with an expansion northwards in the range of I. ricinus.{{cite journal |author=Elisabet Lindgren, Lars Tälleklint & Thomas Polfeldt |year=2000 |title=Impact of climatic change on the northern latitude limit and population density of the disease-transmitting European tick Ixodes ricinus |journal=Environmental Health Perspectives |volume=108 |issue=2 |pages=119–123 |pmid=10656851 |doi=10.2307/3454509 |pmc=1637900 |jstor=3454509}}

I. ricinus is most frequent in habitats where its hosts are plentiful, including woodlands, heaths and forests. It is most prevalent in relatively humid areas, and is absent from much of the Mediterranean Region where summers are dry.

File:19 Ixodes ricinus pareni.tif

Ixodes ricinus has a three-host lifecycle, which usually takes 2–3 years to complete, although it can take from 1 to 6 years in extreme cases. Adults feed on large mammals such as sheep, cattle, dogs, deer, humans, and horses for 6–13 days, before dropping off. An engorged female lays several thousand eggs and subsequently dies. The larvae that hatch do not actively seek a host, and usually feed on insectivores (order Eulipotyphla), although they may also find rodents, rabbits, birds, reptiles, or bats.Mikula, P., Hromada, M., Koleničová, A., Pjenčák, P., Fulín, M., Olekšák, M., 2011. Prevalence of Ticks of birds in Slovak Karst. Folia oecologica presoviensis 5(4): 56-64. They feed for 3–5 days before dropping off and moulting. The resulting nymphs then ascend grasses or twigs to seek their next host, but must return to the moist microclimate at the soil surface if they become dehydrated.{{cite book |author=John L. Capinera |year=2008 |title=Encyclopedia of Entomology |volume=3 |edition=2nd |publisher=Springer |isbn=978-1-4020-6242-1 |chapter-url=https://books.google.com/books?id=i9ITMiiohVQC&pg=PA3788 |chapter=Ticks (Acari: Ixodida) |pages=3733–3802}} The nymphs feed on small to medium-sized mammals.{{cite web |url=http://www.cfsph.iastate.edu/Factsheets/pdfs/ixodes_ricinus.pdf |title=Ixodes ricinus: European Castor Bean Tick, Castor Bean Tick, Sheep Tick |publisher=Iowa State University |date=September 2009}}

A number of tick-borne diseases can be transmitted by I. ricinus to a variety of mammal hosts. Dogs can be infected with Lyme disease (borreliosis), caused by the spirochaete bacteria Borrelia burgdorferi, B. afzelii, and B. garinii. Cattle can become infected with redwater fever (from the protozoans Babesia divergens, B. bovis, and B. ovis), Lyme disease (from B. burgdorferi), sheep tick pyemia (Staphylococcus aureus), cattle tick-borne fever (Anaplasma phagocytophila), Q fever (Coxiella burnetii), Boutonneuse fever (Rickettsia conorii), and the bacterium Anaplasma marginale. Horses may be infected with Lyme disease, Anaplasma phagocytophila, and the viral infection louping ill. Humans can become infected with Lyme disease, louping ill, Q fever, and tick-borne encephalitis, and sensitised{{Cite journal |last=Nunen |first=Sheryl A |date=April 2018 |title=Tick-induced allergies: mammalian meat allergy and tick anaphylaxis |url=https://onlinelibrary.wiley.com/doi/abs/10.5694/mja17.00591 |journal=Medical Journal of Australia |language=en |volume=208 |issue=7 |pages=316–321 |doi=10.5694/mja17.00591 |pmid=29642819 |issn=0025-729X|url-access=subscription }} to mammalian red meat (and derived-products), known as alpha-gal allergy.{{Cite journal |last=Commins |first=Scott P. |date=July 2020 |title=Diagnosis & management of alpha-gal syndrome: lessons from 2,500 patients |journal=Expert Review of Clinical Immunology |volume=16 |issue=7 |pages=667–677 |doi=10.1080/1744666X.2020.1782745 |issn=1744-8409 |pmc=8344025 |pmid=32571129}} The reservoir hosts for the predominant Lymes causing bacteria (Borrelia burgdorferi) are generally smaller vertebrate species - such as birds and rodents - rather than Deer, which are not considered main transmitters of the disease despite the public perception.{{Cite journal|title=Impact of white-tailed deer on the spread of Borrelia burgdorferi|year=2016|last1=Roome|first1=A.|last2=Hill|first2=L.|last3=Al-Feghali|first3=V.|last4=Murnock|first4=C. G.|last5=Goodsell|first5=J. A.|last6=Spathis|first6=R.| last7=Garruto|first7=R. M.|journal=Medical and Veterinary Entomology|volume=31|issue=1|pages=1–122|url= https://doi.org/10.1111/mve.12191|doi= 10.1111/mve.12191|pmid=27699814 }} It is, therefore, more commonly transmitted to humans during the nymph stage. This does not discount Deer as reservoir hosts for other bacteria, such as Anaplasma phagocytophila and Babesia divergens.{{Cite journal|title=Occurrence of tick-borne pathogens in questing Ixodes ricinus ticks from Wester Ross, Northwest Scotland|year=2021|last1=Olsthoorn|first1=F.|last2=Sprong|first2=H.|last3=Fonville|first3=M.|last4=Rocchi|first4=M.|last5=Medlock|first5=J.|last6=Gilbert|first6=L.| last7=Ghazoul|first7=J.|journal=Parasites and Vectors|volume=14|number=430|doi=10.1186/s13071-021-04946-5|doi-access=free |pmid=34446082 |pmc=8393815}}

The parasitic wasp Ixodiphagus hookeri lays its eggs inside castor bean ticks, though the castor bean tick is not I. hookeri's sole host.

The scientific name of the castor bean tick dates back to the starting point of zoological nomenclature, the 1758 tenth edition of Carl Linnaeus' Systema Naturae, where it appeared as Acarus ricinus. Pierre André Latreille split the new genus Ixodes from Linnaeus' Acarus (which at that time contained all known ticks and mites), and I. ricinus was chosen as the type species.{{cite journal |author=Glen M. Kohls |year=1957 |title=Acarina: Ixodoidea |journal=Insects of Micronesia |volume=3 |issue=3 |pages=85–104 |url=http://hbs.bishopmuseum.org/pubs-online/pdf/iom3-3.pdf }} It has subsequently been redescribed under a number of junior synonyms and subsequent combinations into different genera; these synonyms include Acarus ricinoides, Cynorhaestes reduvius, Cynorhaestes ricinus, Ixodes megathyreus, Ixodes bipunctatus, Cynorhaestes hermanni, Crotonus ricinus, Ixodes trabeatus, Ixodes plumbeus, Ixodes reduvius, Ixodes pustularum, Ixodes fodiens, Ixodes rufus, Ixodes sulcatus and Ixodes sciuri.{{cite journal |author=Edward Galton Wheler |year=1906 |title=British ticks |journal=The Journal of Agricultural Science |volume=1 |issue=4 |pages=400–429 |doi=10.1017/S0021859600000447|url=https://zenodo.org/record/2080819 }}

• Ticks of domestic animals

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ricinus

Category:Arachnids of Europe

Category:Arachnids described in 1758

Category:Taxa named by Carl Linnaeus