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Tuatara: Volume 20, Issue 2, March 1973

Additions to the New Zealand Tick Fauna

page 65

Additions to the New Zealand Tick Fauna

Summary

The larva of the endemic species Ixodes jacksoni Hoogstraal is described. I. pterodromae Arthur is recorded from sea birds in the New Zealand Subregion. The Neotropical species I. auritulus Neumann s.s. is recorded from a land bird in the Auckland Islands. The taxonomic status of I. auritulus zealandicus Dumbleton is discussed. Haemaphysalis bispinosa Neumann is replaced by H. longicornis Neumann.

Introduction

The tick fauna of the New Zealand Subregion has been treated in previous papers (Dumbleton, 1944, 1953, 1958, 1961, 1963; Roberts 1970). The present article can be regarded as supplementary to the author's review of the New Zealand tick fauna in Tuatara 11: 72-78. A new endemic sea bird tick, Ixodes jacksoni Hoogstraal (1967), has recently been described from the subregion and the previously undescribed larva of this species is described below. The auritulus-percavatus species group of Ixodes is a difficult one taxonomically and an attempt is made to clarify the identity, occurrence and distribution of those species of this group which occur in the New Zealand Subregion.

Ixodes Jacksoni Hoogstraal 1967

J. Med. Ent. 4: 37-41. (male, female).

The larva, unknown until now, is described below.

Larva

Body (Partly fed) length 1.1 — 1.4mm, width 0.9 — 1.0mm. A smaller species than I. uriae White on the dimensions given for the latter by Arthur (1963).

Capitulum (Fig. 1): ventral length 0.2mm, width 0.13mm, with a posteroventral cordiform swelling. First palpal segment short, transverse, without setae; segments 2 and 3 not separated, without apicomesal gibbosity, length 0.08mm, with 5 setae about mid-length and 5 subapical; segment 4 with 2 long and 4 shorter setae apically and 1 or 2 subapical. Hypostome length 0.1mm, dentition 2-2 with 6 teeth in each file. Only one pair of posthypostomal setae present, on anterior margin of swelling on venter of basis capituli.

page 66
Fig. 1: Ixodes jacksoni larva: capitulum, ventral Fig. 2: Ixodes jacksoni larva: scutum Fig. 3: Ixodes jacksoni larva: dorsal chaetotaxy Fig. 4: Ixodes jacksoni larva: ventral chaetotaxy

Fig. 1: Ixodes jacksoni larva: capitulum, ventral
Fig. 2: Ixodes jacksoni larva: scutum
Fig. 3: Ixodes jacksoni larva: dorsal chaetotaxy
Fig. 4: Ixodes jacksoni larva: ventral chaetotaxy

Scutum (Fig. 2): length 0.3mm, width 0.29mm, widest anteriorly, with 9 structures (5 setae, 4 sensillae) on each side. Eyes absent.

Body setae: (Figs. 3 and 4): 5 pairs centrodorsal, 7 pairs margino-dorsal; 3 pairs sternal, 2 pairs preanal, 1 pair anal, 4 pairs premarginal, 3 pairs marginoventral.

Legs: coxae without internal or external spurs, each with 2 setae. Fore tarsus (Fig. 5) length 0.22mm; dorsal setae; 4 prehalleral, 4 posthalleral, 2 basal; ventral setae; 4 apical, 4 median, 4 basal; Haller's organ with 5 internal processes.

page 67
Fig. 5: Ixodes jacksoni larva: fore tarsus, dorsal

Fig. 5: Ixodes jacksoni larva: fore tarsus, dorsal

Described from 2 larvae collected from a dead Pied Shag (Phalacrocorax punctatus punctatus Sparrman) on New Brighton Beach by Mr J. R. Jackson on 13.1.57. Specimens of Ixodes eudyptidis Maskell were also present on this bird.

The larva resembles the nymph and female of I. jacksoni, and those of the same stages of I. uriae, in having a scutum which is widest anteriorly. Like that of uriae it is distinguished from most other Ixodes species except that of I. kopsteini Oudemans (Roberts, 1969), by the presence of only one pair of posthypostomal setae. Only 3 marginoventral setae are present and the presence of 5 centrodorsal setae is unusual in the genus, but both these conditions exist in I. brunneus Koch (Clifford et al, 1961).

The chaetotaxy of the jacksoni larva coincides with that of uriae as figured by Wilson (1967) but Filippova (1958) figures fewer structures on the scutum of uriae (4 setae only on one side and 4 setae plus 2 sensillae on the other) and additional dorsal setae (1 supplementary seta and 8 marginodorsal setae). The two species are undoubltedly con-subgeneric on characters of all stages. The apparent subdivision of the ventral plates of the males of uriae appears to be due to differences in pigmentation colour rather than in structure. I. jacksoni, endemic on the New Zealand mainland, is the only species which is closely related to the distinctive seabird species I. uriae, which in spite of its bipolar distribution gives no evidence of subspeciation. The only host of jacksoni known so far is a rather sedentary cormorant species nesting on rocky coasts, and the only locality records are from Banks Peninsula, or its vicinity, in the South Island, though colonies of the host species occur in the northern part of the North Island. Ixodes uriae on the other hand occurs commonly on various seabirds, including cormorants, in the New Zealand Subantarctic but appears rarely to breed on the New Zealand mainland. There are three records (Dumbleton 1953, 1961) of the occurrence of uriae in mainland localities but one of these was based on a misidentification of jacksoni, another page 68 was from a host which does not breed in New Zealand proper, and only one was from a host (Eudyptes pachyrhynchus Gray) which does breed on the mainland.
Fig. 6: I. pterodromae female (Birdlings Flat): first palpal segment, dorsal. Fig. 7: I. pterodromae female (Birdlings Flat): first palpal segment, externo-lateral.

Fig. 6: I. pterodromae female (Birdlings Flat): first palpal segment, dorsal.
Fig. 7: I. pterodromae female (Birdlings Flat): first palpal segment, externo-lateral.

Additional records of jacksoni are:—

Lake Forsyth: female ex Pied Shag, J. R. Jackson, 21.xii.57 (with Ornithodorus capensis Neumann); Birdlings Flat; nymphs ex Pied Shag nests, L. J. Dumbleton, 24.xi.57 (with I. eudyptidis and O. capensis).

Ixodes Pterodromae Arthur 1960

Parasitology 50: 217-23 (female). Roberts 1960, Aust. J. Zool. 8: 414-7; 1964 J. ent. Soc. Qd. 3: 75-6 (male).

Tick specimens collected from sea birds in the New Zealand Subregion and belonging to the auritulus-percavatus group of Ixodes were originally considered (Dumbleton, 1953) to be I. auritulus Neumann 1904, a species nearly related to I. percavatus Neumann 1906 from sea birds on Nightingale Is. (Tristan da Cunha) by their common possession of an anterior prolongation of the inner side of the first palpal segment (Fig. 6). Zumpt (1952) and Arthur page 69 (1953) considered percavatus to be a synoym of auritulus but Arthur (1960) re-established percavatus as a valid species distinguished by the possession of a basodorsal spur on the first palpal segment (Fig. 7) and described the females of three new species which possess a similar structure. The identity and host relationships of I. cornuae are in some doubt since no holotype was designated. The syntypes include 3 females ex a species of quail Equateur, Dr Rivet 1901, and 1 female and nymphs, Baie Orange, Mission du Cap Horn 1882-8, Dr Hyades and Sauvinet. The Equateur specimens are not only from a landbird but are apparently from Equateur since Dr G. Rivet collected there in this period with a French Army Mission measuring an equatorial are of meridian (Becker, 1919). I. zumpti Arthur was based on three females from sea birds (Puffinus, Diomedea, Phebetus spp.), Nightingale Is., Tristan da Cunha. I. pterodromae Arthur was based on two females from sea birds (Pterodroma spp.) from Marion Is, Indian Ocean. Roberts (1960, 1964) recorded pterodromae and described the male from Macquarie Is. and Wilson (1964) recorded the species from Campbell Is.

Three records of auritulus s.s. from the New Zealand Subantarctic (Dumbleton, 1953) are now considered to be based on probable misidentifications of pterodromae. The Antipodes Is. record was based on a nymph, a stage which is difficult to identify with certainty in this species group.

The specimens on which were based two early records of auritulus from Macquarie Is. have not been located but later collections from there have been exclusively pterodromae (Roberts, 1960, 1964a). It is possible that pterodromae itself may eventually be found to be a synonym of the older species percavatus.

Specimens determined as pterodromae have been collected as follows:—

Ocean Is. Auckland Is.): male among plants, P. M. Johns, 28.xii.62, det. F. H. S. Roberts; females and nymphs ex burrows of Subantarctic Diving Petrel (Pelecanoides exsul Salvin). L. J. Dumbleton, 29.xii.62.

Birdlings Flat: females ex Sooty Shearwater (Puffinus griseus Gmelin) M. Fitzgerald, 16.i.63, det. F. H. S. Roberts.

Ixodes Auritulus Neumann 1904

Arch. de. Parasitol., 8: 450 (female); Arthur 1960, Parasit. 50: 201-12; Kohls and Clifford 1966, J. Parasit. 52: 815-7 (male).

Female: Body length (excluding capitulum) 6.4mm, width 5.0mm in engorged female; 2.6 × 1.8 to 3.8 × 2.6 in others. Colour yellowish-white in unengorged females, greyish-white in engorged female.

Capitulum ventral length 0.79mm. Basis widest 0.47mm across bases of cornuae; cornuae equilateral-triangular with slightly convex page 70 sides and blunt apex; posterior margin of basis nearly straight. Porose areas large subovoid occupying most of basis and separated by nonporose median area of variable width. Palps with 1st segment produced anteriorly on inner side with subconical dorsoapical spur, without basodorsal spur; 2nd and 3rd segments 0.32mm long, slightly clavate, suture between the two segments faint but 2 slightly longer than 3. Ventrally the sides of the basis are straight and diverging posteriorly, becoming slightly convex on the outer side of the auricula. Auricula retrograde, apex blunt, inner margin convex becoming concave basally. Posterior ventral margin of capitulum convex semicircular. Hypostome long, only slightly spatulate, rounded apically, dentition 4-4, about 12 teeth in outer file. Scutum suboval, longer than wide, length - width ratio 1.2 — 1.5, little anterior emargination, scapulae small, widest at midlength, anterolateral side slightly concave, lateral angle rounded, posterolateral side with slight, concavity at end of cervical groove, posterior margin broadly rounded. Colour yellowish brown except narrow cervical groove, a transverse anterior band and the outer half of the sub-marginal area between the cervical groove and the margin on which the punctation is most evident. Legs: Coxae with 4 prominent stout setae on posterior submargin, 3 between the internal and external spurs and one on the outer base of the external spur. The external spur on fore coxae not markedly larger than those on other coxae. Coxa I with 1 anterointernal seta and several large and subacute, the posterior margin between them deeply concave. Coxa II with shorter blunter internal spur and large external spur, the posterior margin between them more widely but less deeply concave. Coxa III with short blunt internal spur but large external spur, the margin between them straighter and shallower. Coxa IV with a broad trenchant edge or sometimes a very small spur internally, the external spur large and the posterior margin between them nearly straight. All trochanters with ventral spurs and first two with small dorsal spurs.

Genital aperture between coxae III. Genital grooves straight.

Anal grooves subparallel posteriorly. Spiracular plate subcircular, the macula slightly anterior of centre.

Described from 5 females ex Auckland Is. Snipe (Coenocorypha aucklandica Gray), collected by P. M. Johns on Ewing Is. (Auckland Is.) on -.i.63.

The characters of the first palpal segment in these specimens conform with those of the predominantly land bird infesting American species I. auritulus, and the coxal characters are very similar to those of Guatemalan specimens of this species figured by Arthur (1960). Males are not known and there is insufficient evidence to determine whether the Auckland Is. population should be regarded as a distinct subspecies. The probable validity of the record is strengthened by Robert's (1964b) record of auritulus s.s. from two land birds, Strepera fuliginosa Gould (Black Currawong) and Sericornis page 71 humilis Gould (Brown Scrub Wren), in Tasmania. Dr Roberts who examined an Auckland Is. specimen agrees on its identity with his Tasmanian specimens.

It is not possible to decide between the possible explanations of the disjunct distribution of auritulus s.o. It seems improbable that the Auckland Is. and Tasmanian occurrences could be attributed to chance dispersals of auritulus from America on migrating birds, since it occurs characteristically on land birds and the migratory land bird species coming to New Zealand are largely or exclusively from Asia rather than America. A second possibility is that the Auckland Is. population segregated from I. pterodromae in an environment where the habitats of land and sea birds were contiguous, and that its morphological similarity to auritulus resulted from convergent evolution. Such a segregation has been suggested by Smit (1965) to explain the origin of the New Zealand parrot flea Parasyllus nestoris Smit from one of the other species of the endemic P. cardinis group, all of which occur on sea birds. It seems unlikely however that a species which segregated on land birds in the Auckland Is. could have dispersed to Tasmania (or vice versa), or that there were independent segregations of morphologically identical species on both islands. The occurrence of auritulus in southern Chile, Auckland Is., and Tasmania suggests the austral type of distribution which characterises many other southern hemisphere taxa. The Tasmanian and Auckland Is. populations would then be regarded as relict. The fact that auritulus occurs in both North and South America, while inconsistent with the restricted southern hemisphere temperate zone distributions of typically austral taxa, does not necessarily negative this explanation.

Ixodes Auritulus Zealandious Dumbleton 1961

N.Z. Jl. Sci. 4: 765-6.

A male Ixodes from the nest of a sea bird (Pelecanoides chathamensis) on Snares Is. 90 miles south of New Zealand was described and figured (Dumbleton, 1953) as the previously unknown male of I. auritulus Neumann sensu stricto, a species described from an unknown host in southern Chile but occurring commonly (possibly exclusively) on land birds in both the Neotropical and Nearctic Regions. Associated females from the Snares Is. and from a burrow-nesting sea bird (Pachyptila turtur (Kuhl)) on Stephen Is. in Cook Strait (in addition to others from islands in the New Zealand Subantarctic) were also considered to be auritulus s.s., Arthur (1960) who redescribed and figured the Snares Is. specimens and accepted their close affinity with auritulus s.s. but pointed out morphological features in which the New Zealand specimens differed. Dumbleton (1961) gave the Snares Is. (male holotype and female paratype) and page 72 Stephen Is. (male and female paratypes) specimens taxonomic status as the subspecies zealandicus of auritulus. Zumpt (1952) mentioned two females in the British Museum from a ‘dove petrel’ on Stephen Is. which he identified as auritulus s.s. These are probably zealandicus since they appear to be from the same host and locality as paratypes of this subspecies.

The anterior prolongation of the inner side of the first palpal segment of the female places the subspecies as belonging to the auritulus-percavatus group. The absence or weak development of the baso-dorsal spur on this segment in the Snares Is. paratype female (Arthur, 1960) suggests affinity with auritulus. This structure is however more strongly developed in two Stephen Is. paratype females, and its range of variation in pterodromae and other members of the percavatus complex is imperfectly known. The female of zealandicus differs from that of auritulus s.s. in the greater length and subrectangular shape of the 2nd and 3rd coxae and resembles percavatus rather than pterodromae in the absence of acute internal spurs on both of these.

The presumed male of auritulus s.s., subsequently described by Kohls and Clifford (1966) from an unknown host in southern Chile, was stated to differ from that of zealandicus in the more numerous hypostomal teeth (3-3 in anterior third, increasing to 6-6 or 7-7 at midlength, decreasing to base), the presence of a distinct median scutal elevation and a pit-like dorsolateral depression on each side of the scutum just before midlength, and the longer and more densely setose fore tarsi. As figured it differs also in that the anterior mesal margin of the epimeral plate does not terminate on the anterior mesal margin of the spiracular plate but continues to the 4th coxae. The median plate is longer in relation to its width (L-W 1.4) and is as wide at midlength as posteriorly. The anal grooves are strongly converging posteriorly and all coxae have small external spurs. These differences are greater than would be expected if zealandicus were a subspecies of auritulus.

The male of zealandicus moreover closely resembles the male of pterodromae described by Roberts (1964a) from nests of Pachypila desolata Gmelin on Macquarie Is., though the latter is stated to have a 5-5 — 6-6 hypostomal dentition.

The taxon is retained as a subspecies of auritulus only because the evidence is inconclusive. Specimens from the New Zealand Subregion which are morphologically identical with those of the nominate subspecies of auritulus from the Americas are also consistent in their host association in that they are from a land bird, but the occurrence of auritulus zealandicus on sea birds is anomalous and considerations of distribution also suggest that its relationships, whether as a distinct species or as a subspecies, may be with pterodromae.

page 73

Haemaphysalis Longicornis Neumann 1901

Haemaphysalis longicornis Neumann, 1901, p.261, fig. 2 (Neumann 1901) Hoogstraal et al (1968) consider that the species from Australia, New Zealand, Fiji and Noumea, determined as bispinosa is not bispinosa of Neumann (1897), and have resurrected for it longicornis Neumann 1901.

Acknowledgements

I am indebted to Messrs M. Fitzgerald, J. R. Jackson, and P. M. Johns of Christchurch for the gift of specimens, and to Dr. F. H. S. Roberts of Brisbane for the loan of specimens and for opinions on the identity of specimens submitted to him.

References

Arthur, D. R. 1953: The systematic status of Ixodes percavatus var. rothschildi Nuttall and Warburton. Parasitology 43: 222-6.

——, 1960: A review of some ticks (Acarina: Ixodidae) of sea birds. Part II: The taxonomic problems associated with the Ixodes auritulus-percavatus group of species. Ibid 50: 199-226.

——, 1963: ‘British Ticks.’ Butterworths, London. 213pp.

Becker, T. 1919: Dipteres Brachyceras pp. 163-215. IN Mission du Service Geographique de l'Armee pour le Mesure d'un Are de Meridien Equatorial en Amerique de Sud, 1899-1906. Tome 10, fasc. 2. Paris, Gauthier-Villars.

Clifford, C. M., Anastos, G., Elbl, A. 1961: The larval ixodid tricks of the eastern United States (Acarina-Ixodidae) Misc. pub. ent. Soc. Amer. 2: 213-37.

Dumbleton, L. J. 1944: A new tick from the Tuatara (Sphenodon punctatus) N.Z. J. Sci. and Tech. 24B: 185-190.

——, 1953: The Ticks (Ixodoidea) of the New Zealand Subregion. N.Z. Cape Exped. Ser. Bull. 14: 1-28.

——, 1958: The occurrence of an Argasid Tick in New Zealand. N.Z. J. Sci. 1: 570-8.

——, 1961: The Ticks (Acarina: Ixodoidae) of Sea Birds in New Zealand waters. Ibid 4: 760-9.

——, 1963: A Synopsis of the Ticks (Acarina: Ixodoidae) of New Zealand. Tuatara 11: 72-8.

Filippova, N. A. 1958: Materials concerning larvae and nymphs of sub-family Ixodinae Banks, 1907. Parazitol. Sb. Zool. Inst. Akad. Nauk. S.S.S.R. 18: 10-77.

Hoogstraal, H. 1967: Ixodes jacksoni n.sp. (Ixodoidea: Ixodidae), a nest parasite of the spotted cormorant, Phalacrocorax punctatus (Sparrman) in New Zealand. J. med. Ent. 4: 37-41.

——, Roberts, F. H. S., Kohls, G. M., Tipton, V. J. 1968: Review of Haemaphysalis (Kaiseriana) longicornis Neumann (Resurrected) of Australia, New Zealand, New Caledonia, Fiji, Japan, Korea, and Northeastern China and U.S.S.R., and its parthenogenetic and bisexual populations (Ixodoidae: Ixodidae). J. Parasit. 54: 1197-1213.

Kohls, G. M., Clifford, C. M. 1966: Three new species of Ixodes from Mexico and description of the male of I. auritulus auritulus Neumann, I. conepati Cooley and Kohls, and I. lasallei Mendez and Ortiz (Acarina: Ixodidae). J. Parasit. 52: 810-820.

Neumann, L. G. 1901: Revision de la famille des Ixodides. Mem. Soc. Zool. Fr. 14: 249-372.

Roberts, F. H. S. 1960: A systematic study of the Australian species of the genus Ixodes (Acarina: Ixodidae). Aust. J. Zool. 8: 392-485.

——, 1964a: The males of Ixodes pterodromae Arthur and Ixodes australiensis Neumann (Acarina: Ixodidae). J. ent. Soc. Qd. 3: 75-8.

——, 1964b: The Tick Fauna of Tasmania. Rec. Queen Victoria Mus. Launceston N.S. 17: 3-8.

——, 1969: The larvae of Australian Ixodidae (Acarina: Ixodoidae). J. Aust. Entomological Soc. 8: 37-78.

——, 1970: Australian Ticks. Commonwealth Scientific and Industrial Research Organisation, Australia.

Smit, F. G. A. N. 1965: Siphonaptera of New Zealand. Trans. R. Soc. N.Z. (Zool.) 7: 1-50.

Wilson, N. 1964: Insects of Campbell Island. Metastigmata: Ixodidae. Pacif. Insects Monogr. 7: 132-7.

——, 1967: Mesostigmata: Thinonyssidae, Halarachnidae (Nasal Mites); Metastigmata; Ixodidae (Ticks). In Entomology of Antarctica ed. J. L. Gressitt Antarctic Research Series 10: 41-9.

Zumpt, F. 1962: The Ticks of Sea Birds. Aust. nat. Antarctic Res. Rep., ser. B. 1: 12-20.