Ixodes auritulus female (figure adapted from Arthur (1960)) (click on thumbnail for larger image).

Ixodes auritulus male (figure adapted from Dumbleton (1953)) (click on thumbnail for larger image).

Species name

Ixodes auritulus Neumann, 1904

Common name

-

Naming history

Ixodes auritulus Neumann, 1904 (accepted name)

Synonyms and misapplied names:
Ixodes auritulus auritulus Kohls & Clifford, 1966 (synonym)
Ixodes percavatus Zumpt, 1952 (misapplied name)
Ixodes thoracicus Neumann, 1899 (misapplied name)
Ixodes (Ixodes) auritulus Neumann, 1904 (synonym)
Ixodes (Multidentatus) auritulus Clifford et al ., 1973 (synonym)
Scaphixodes (Multidentatus) auritulus Camicas et al ., 1998 (synonym)

Hosts

Usually associated with burrowing sea birds, however, there are some exceptions.  Hosts include common diving petrel (Pelecanoides urinatrix), fairy prion (Pachyptila turtur), sooty shearwater (Puffinus griseus), Hutton's shearwater (Puffinus huttoni), grey petrel (Procellaria cinerea), broad- billed prion (Pachyptila vittata) and Stewart Island weka (Gallirallus australis scotti), Stewart Island snipe (Coenocorypha aucklandica iredalei), little blue penguin (Eudyptula minor), western weka (Gallirallus australis australis), Auckland Island snipe (Coenocorypha aucklandica aucklandica), wandering/snowy albatross (Diomedea exulans exulans), South Island Kaka (Nestor meridionalis meridionalis), black-browed albatross/mollymawk (Diomedea melanophrys melanophrys), Fulmar prion (Pachyptila crassirostris crassirostris), yellow-eyed penguin (Megadyptes antipodes), black-bellied storm petrel (Fregetta tropica), Buller's shearwater (Puffinus bulleri) and kakapo (Strigops habroptila) (ACG Heath, AgResearch, unpub. data); South Island saddleback (Philesturnus carunculatus carunculatus), Southern diving petrel (Pelecanoides urinatrix chathamensis), Antarctic tern (Sterna vittata bethunei), flesh-footed shearwater (Puffinus carneipes hullianus), Snares penguin (Eudyptes robustus), black-backed gull (Larus dominicanus), Antipodes Island snipe (Coenocorypha aucklandica meinertzhagenae).

Description of larva

Not available at present

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Description of nymph

Adapted from Dumbleton (1953), Arthur (1960) and Roberts (1970).

• Body unfed specimen oval, 1.15 by 0.70 mm; marginal groove distinct; hairs few and scattered.
• Capitulum length 0.3 mm.
  •  Basis capituli dorsally 0.22 mm wide, form as in female; cornua distinct; basis ventrally rounded posteriorly, constricted in region of auriculae, which are long, pointed, and somewhat divergent.
  • Palps clavate; article (segment) 1 as in female; articles (segments) 2 and 3 0.15 mm in length.
  • Hypostome broadly rounded distally; dentition 3 rows of 2/2 basally then 4 or 5 rows of 3/3 and one row of 4/4 towards apex.
• Scutum shape as in female, but a little broader in relation to length, approximately 0.58 by 0.45 mm; surface granulated, no obvious punctations. Cervical grooves distinct, attaining scutal margin. Emargination almost obsolete.
• Legs
  • Coxae  coxal spurs much as in female, but more pointed.
  • Trochanters trochantal spurs as in female, that on trochanter IV small.
  • Tarsi slender and tapering; length of tarsus I 0.40 mm, and of tarsus IV 0.39 mm.
    

Description of female

Adapted from Dumbleton (1953), Arthur (1960) and Roberts (1970).

• Capitulum length 0.69 mm.
  • Basis capituli dorsally smooth, 0.55 mm in width; posterior margin almost straight; cornua large, bluntly pointed; posterolateral margins strongly curved; porose areas large, transversely oval, the interval not quite half the width of one; basis ventrally smooth, constricted at level of auriculae, which are large, heavy, retrograde horns.
  • Palps clavate; article 1 with a well developed, internal, anterior, pointed horn-like projection; articles 2 and 3 with indistinct suture, gently curved externally, almost straight internally, length 0.37 mm and almost four times the greatest width.
  • Hypostome wide broadly rounded apically, about 0.32 mm in length. Dentition variable 6/6 then 5/5 or 3/3 apically, then 4/4 and 3/3 at the base.
• Scutum elongate oval, 1.32 by 0.90 mm, widest a little anterior to mid-length; anterolateral margins mildly concave; posterolateral margins mildly convex; posterior angle broadly rounded. No lateral carinae. Punctations moderate in number, shallow, distributed mainly anteriorly and laterally. Cervical grooves narrow and shallow posteriorly, almost attaining the scutal margin. Emargination very shallow.
• Genital aperture on a level with third intercoxal space.
• Spiracular plate subcircular, a little flattened ventrally.
• Legs moderate to long in length amy appear thin; hairs few.
  • Coxae smooth, with few long hairs; internal spur on coxa I, broad, pointed, those on coxae II and III smaller, and on coxa IV at most a mild salience; external spur on all coxae large and slightly inwardly directed, that on coxa IV a little smaller than those on coxae II and III.
  • Trochaters trochantal spurs strong, but smaller than external cozal spurs.
  • Tarsi long and tapering, each with a mild subterminal hump; tarsus IV 0.68 mm in length.
    

Description of male

From Dumbleton (1953).

• Body oval; length including capitulum 25 mm., width 17 mm.
• Capitulum
  • Basis capituli widest, 0.24 mm, immediately behind the palps, lateral margins convergent posteriorly but not as abruptly as in I. anatis. Ventrally with two pairs of setae on basis behind first palpal article. Cornua absent. Dorsally the basis capituli is separated from the neck by a short carina. Neck with sides slightly divergent posteriorly, a group of 6-8 setae on each side at mid length. Ventrally the basis capituli ends posteriorly in a rounded line separating it from the neck. Auriculae absent.
  • Palpi short, rounded apically; article (segment) 1 short, articles (segments) 2 and 3 not divided, combined length 0.19 mm; articles 4 small, rounded.
  • Hypostome small, tapering, length 0.15 mm. Dentition 3/3 then 4/4, with about 10 teeth per file, files not marked, rows of denticles transverse, lateral and median denticles not markedly different.
• Scutum length 1.8 mm, width 1.2 mm; impunctate, shining, hairless, castaneous; scapulae small and rounded. Cervical grooves faint and shallow, lateral carina absent, lateral groove present.
• Ventral plates impunctate, hairless except for scattered short setae on median and posterior plates, castaneous. Median plate nearly as wide as long, length 0.9 mm. Adanal plate widest anteriorly. Epimeral plate contiguous with spiracular plate and mesally extending to the anterior margin of the spiracular plate. Anal plate rounded anteriorly, sides sub-parallel. Pregenital plate sub-pentagonal, posterolateral sides notched at mid length. Between the pregenital plate and coxae 1 on each side is a small oblique rectangular sclerite-the jugum or jugular plate.
• Legs
  • Coxae contiguous. Coxa 1 without external or internal posterior spur but with an anterior external gibbous process. Coxa 2 without spur, coxae 3 and 4 with small posterior external spurs.
  • Trochanters with posterior gibbosity decreasing in strength on posterior coxae and absent on 4.
  • Tarsi Tarsus 1, 0.52 mm long, tarsus 4 tapering gradually, 0.26 mm long, metatarsus 4, 0.13 mm long.
• Spiracular plate sub-circular 022 mm long, 017 mm wide, macula central.
• Genital aperture between coxae 3.
• Anus three pairs of setae.
  

Disease relationships

This section needs to be updated.

Distribution

Antarctica, Argentina, Brazil, Canada, Chile, Costa Rica, Ecuador, Guatemala, New Zealand, United States, Uruguay, Venezuela.

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Status in New Zealand

Endemic/naturalised

Comments, identifying features and similar species

Ixodes auritulus is a three host tike that is nitidulous (the off host period is spent in the hosts burrow).  It is thought that male Ixodes auritulus are restricted to the host habitat while the females, nymphs and larvae are all found on the same hosts.  The auritulus complex is widely distributed in the southern hemisphere and extends to the west coast of North America in the northern hemisphere.  It is fairly common on sea birds, but in North and South America the hosts ar species of land birds.

Ixodes auritulus can be distinguished from other Ixodes species that occur in New Zealand by the following features;

• Hosts: sea birds
• Males: Dentition of the hypostome 4/4, toothed area long; second palpal article (segment) gradually narrowing basally; anal grooves slightly diverging.
• Females: Basis capituli with cornua and retrograde (horn-like) auriculae; porose areas oval; palpal article (segment) 1 with only a internal forwardly directed spur. 
• Nymphs: Palpal article (segment) 1 with only a internal forwardly directed spur.

The female and nymph of I. auritulus can potentially be confused with that of I. kerguelenensis.  However but are readily identified by the absence of a mesodorsal spur on palpal article (segment) 1.

Useful references

Arthur DR 1960. A review of some ticks (Acarina: Ixodidae) of sea birds. Part II.  The taxonomic problem associated with Ixodes auritulus-pervcavatus group of species. Parasitology, 50: 199-226.

Barker SC & Murrell A  2004.  Systematics and evolution of ticks with a list of valid genus and species names.  Parasitology, 129: S15-S36.

Bishop DM. & Heath ACG 1998. Checklist of ectoparasites of birds in New Zealand. Surveillance. Special Issue: Parasites of Birds in New Zealand. 25: 13-31.

Camicas JL, Hervy JP, Adam F & Morel PC 1998.  Les Tiques de Monde.  Nomenclature, stades decrits, hotes, repartition.  The ticks of the world.  Nomenclature, described stages, hosts, distribution (Acarida, Ixodida). France , Orstom Editions.

Dumbleton LJ 1953. The ticks (Ixodoidea) of the New Zealand sub-region. New Zealand Cape Expedition Series Bulletin, 14: 1-28.

Dumbleton LJ 1961. The ticks (Acarina: Ixodoidea) of sea birds in New Zealand waters. New Zealand Journal of Science, 4: 760-769.

Dumbleton LJ 1963. A synopsis of the ticks (Acarina: Ixodoidea) of New Zealand. Tuatara 11: 72-78.

Heath ACG 1987. A review of the origins and zoogeography of tick-borne disease in New Zealand. Tuatara 29: 19-29.

Heath ACG 2006. Observations on Ixodes eudyptidis Maskell (Acari: Ixodidae), Ornithodoros capensis Neumann (Acari: Argasidae), and other tick parasites of sea birds in New Zealand. Systematic and Applied Acarology: 11: 131-140.

Horack IG, Camicas J-L & Kierans, JE 2002. The Argasidae, Ixodidae and Nuttalliellidae (Acari: Ixodida): a world list of valid tick names.  Experimental and Applied Acarology, 28: 27-54.

Roberts FHS 1970. Australian ticks. Commonwealth Scientific and Industrial Research Organisation, Melbourne, 267pp.