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

Ixodes kerguelenensis male figure adapted from Roberts (1970) (click on thumbnail for larger image).

Species name

Ixodes kerguelenensis Andr� & Colas-Belcour, 1942

Common name

-

Naming history

Ixodes kerguelenensis Andr� & Colas-Belcour, 1942 (accepted name)

Synonyms and misapplied names:
Ixodes canisuga kerguelenensis Zumpt, 1952 (synonym)
Ixodes canisuga v. kerguelenensis Andr� & Colas-Belcour, 1942 (synonym)
Ixodes percavatus Andr�, 1947 (misapplied name)
Ixodes pterodromae Arthur, 1960 (synonym)
Ixodes zumpti Arthur, 1960 (synonym)
Ixodes (Multidentatus) kerguelenensis Clifford et al., 1973 (synonym)
Scaphixodes (Multidentatus) kerguelenensis Camicas et al., 1998 (synonym)

Hosts

Seabirds including wandering albatross (Diomedea bulleri), fleshy-footed shearwater (Puffinus carneipes), Tasmanian mutton bird (Puffinus tenuirostris)

Description of larva

Not available at present

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Description of nymph

From Roberts (1970).

• Body unfed specimen 1.3 by 1.0 mm, marginal grooves apparent, hairs scattered; engorged specimens attaining 3.5 by 2.5 mm.
• Capitulum Length 0.30-0.35 mm.
  • Basis capituli dorsally 0.25-0.28 mm in width, shape as in female; surface sometimes with some punctations in region of porose areas; cornua strong, divergent; auriculae strong.
  • Palpi with article I with internal anteriorly directed, horn-like process and mesodorsal spur; articles 2 and 3 clavate, about 0.19 mm in length.
  • Hypostome about 0.21 mm in length, broadly rounded distally; dentition mainly 3/3, becoming 2/2 basally.
• Scutum longer than wide, 0.60 by 0.50 mm. Punctations few, not as obvious as in female. Cervical grooves, emargination and scapulae as in female.
• Anal grooves as in female.
• Spiracular plate Broadly oval to subcircular; greatest dimension 0.24 mm.
• Legs
  • Coxae as in female.
  • Trochanters as in female.
  • Tarsi as in female.

Description of female

From Roberts (1970).

• Body unfed specimen 2.3 by 1.5 mm, marginal groove distinct; engorged specimens attaining 10.8 by 6.2 mm, marginal groove not apparent; hairs pale, short, scattered.
• Capitulum length 0.58-0.69 mm.
  • Basis capituli dorsally 0.46-0.48 mm in width, surface flat; posterior margin sinuous or almost straight; cornua prominent, dark, broad and blunt; posterolateral margin strongly curved;
  • Porose areas, large, transversely oval to subcircular, almost contiguous with posterior margin of basis, interval narrow; basis ventrally rounded posteriorly, constricted in region of auriculae which are large, strong, blunt spurs with mildly curved or almost straight lateral margins.
  • Palpi clavate; article 1 large, with a prominent internal anteriorly directed and dorsally curving horn-like process, and a distinct mesodorsal spur; articles 2 and 3 with indistinct suture, 0.30-0.38 mm in length; hairs relatively few and short.
  • Hypostome spatulate, broadly rounded distally; some minute teeth distally, larger teeth mainly 4/4, becoming 3/3, 2/2, and sometimes 1/1 basally.
• Scutum elongate, suboval, 1.10 by 0.86 mm-1.32 by 1.01 mm, widest anteriorly; anterolateral margins mildly convex or straight, posterolateral margins mildly convex, posterior angle broadly rounded. Punctations few to moderate in number, shallow, mainly fine, with some larger punctations, sometimes confluent, laterally. No lateral carinae. Cervical grooves long and distinct, not quite attaining scutal margin. Emargination shallow. Scapulae shallow and rounded.
• Genital aperture on a level with coxa III.
• Anal grooves broadly rounded anteriorly, mildly constricted posteriorly.
• Spiracular plate broadly oval to subcircular, the longer axis transverse; greatest dimension 0.31-0.36 mm.
• Legs moderate in length, articulations pale.
• Coxae smooth, with a few long hairs on posterior margin; coxa I with broad, blunt, internal spur; internal spur on coxa II and III less prominent and more pointed, coxa IV without internal spur, all coxae with external spur, that on coxa I large and heavy, smaller on coxae II-IV.
• Trochanters with heavy, ventral spurs, almost as large as emternal coxal spurs; trochanter I with well developed dorsal spur, asimilar, but smaller spur on trochanter II.
• Tarsi long, II-IV tapering gradually, I more abruptly, each with a subapical hump, most distinct on tarsus I; length of tarsus I 0.72-0.82 mm, and of tarsus IV 0.68-0.83 mm.
  

Description of male

From Roberts (1970).

• Body oval, 2.7 by 1.9 mm-3.2 by 2.0 mm, brown, without obvious punctations; marginal body fold prominent, commencing near scapulae, the groove deep.
• Capitulum length 0.43-0.45 mm.
  • Basis capituli dorsally punctate, 0.28-0.31 mm wide; posterior margin dark, straight; no cornua; posterolateral margins practically straight, divergent anteriorly; basis ventrally broadly rounded posteriorly; no auriculae.
  • Palpi short, club-shaped, 0.3 mm in length; articles 2 and 3 without apparent suture, 0.26-0.28 mm in length, with maximum width of 0.14-0.16 mm at about mid-length; article 1 globular, wider than long and with a distinct mesoventral ridge which continues along articles 2 and 3.
  • Hypostome broad, narrowing towards apex which is flattened and indented medianly; length 0.20 mm; some broadly rounded teeth and crenulations distally followed by about 5 or 6 rows of 5/5-6/6 bluntly pointed teeth, then some rows of small rounded teeth basally.
• Scutum oval, strongly convex, shining and devoid of punctations, 2.3 by 1.4 mm-2.7 by 1.5 mm. No lateral carinae or lateral grooves. Pseudoscutum indistinct. Cervical grooves short, shallow. Emargination mild. Scapulae broad, shallow, rounded. Hairs sparse, minute.
• Genital aperture on a level with second intercoxal space.
• Ventral plates Impunctate and practically hairless. Pregenital plate subhexagonal and notched laterally, moderate in size and almost as wide as long; jugular plate small, subrectangular and internal to coxa I; median plate longer than wide, 1.1 by l.0 mm-1.4 by 1.2 mm; anal plate rounded anteriorly, mildly constricted posteriorly; adanal plate subrectangular, a little wider anteriorly than posteriorly; epimeral plate, elongate subtriangular, its anterior margin practically level with anterior margin of spiracular plate.
• Spiracular plate subcircular, greatest dimension 0.31 mm.
• Legs Slender.
  • Coxae close together; coxae I-III each with a dark posterointernal salience, strongest and spur-like on coxa I, and least distinct on coxa III; coxae II-IV each with a small posteroexternal spur, represented on coxa I by a mild, rounded salience; small anteroexternal prominences on all coxae, mild and pointed on coxa I, rounded on coxa II, and somewhat spur-like on coxae III and IV. Trochanters without spurs.
  • Tarsi slender and tapering gradually; length of tarsus I 0.77-0.79 mm, and of tarsus IV 0.67-0.75 mm.
    

Disease relationships

This section needs to be updated.

Distribution

New Zealand: South Georgia, Prince Edward, Crozets, Kerguelen, Heard, Maquarie, Auckland, Lord-Haw, and Campbell Islands.
Shores of Australia: (South Australia and Tasmania).

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Status in New Zealand

Endemic/naturalised

Comments, identifying features and similar species

Ixodes kerguelenensis is a three host tick that is associated with seabirds and is nitidulous (the off host period is spent in the hosts burrow).  It is thought that male I. kerguelenensis are restricted to the host habitat while the females, nymphs and larvae are all found on the same hosts.

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

• Hosts: Sea birds
• Males: The males of I. kerguelenensis   can be separated from other species of Ixodes that occur in New Zealand by, the coxal armature; the hypostomal dentition being 5/5-6/6; palpal article 2 rapidly narrowing basally giving the palp a club shaped appearance and the anal groove being slightly constricted medianly.
• Females: The females of I. kerguelenensis  can be separated from other species of Ixodes in New Zealand by the coxal armature, and the presence of both an internal forwardly directed spur and a mesodorsal spur on palpal article 1.
• Nymphs: The nymphs of I. kerguelenensis can be separated from other species Ixodes in New Zealand by the presence of both an internal forwardly directed spur and a mesodorsal spur on palpal article 1.

The female and nymph of I. kerguelenensis can potentially be confused with that of I. autritulus.  However, I. kerguelenensis is readily identified by the presence of both an internal forwardly directed spur and a mesodorsal spur on palpal article 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.

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.

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

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 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.

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.

Wilson N (1964) Insects of Campbell Island. Metastigmata: Ixodidae. Pacific Insects Monographs, 7: 132-137.