Ixodes laridis Heath & Palma, 2017

Palma, Ricardo L., 2017, A new species of tick (Acari: Ixodidae) from seabirds in New Zealand and Australia, previously misidentified as Ixodes eudyptidis, Zootaxa 4324 (2), pp. 285-314 : 286-288

Ixodes laridis Heath & Palma new species

( Figs 1–2, 5 , 7–11, 13,15 , 17–19 , 21 ¯33, 35, 37, 39, 41, 43, 45)

Ixodes eudyptidis Maskell, 1885 ; Dumbleton 1953: 12, pl. 3, figs 5–8. In part: larva only. Ixodes eudyptidis Maskell, 1885 ; Dumbleton 1961: 765. In part.

“ Ixodes eudyptidis ” Green & Macdonald, 1963: 184. Not Ixodes eudyptidis Maskell, 1885 . Ixodes eudyptidis Maskell, 1885 ; Roberts 1964: 3. In part.

Ixodes eudyptidis Maskell, 1885 ; Roberts 1970: 21, fig. 6. In part: female only.

“ Ixodes eudyptidis ” St. George et al., 1977: 493. Not Ixodes eudyptidis Maskell, 1885 . Ixodes eudyptidis Maskell, 1885 ; Heath 1977: 30, figs 1–2. In part.

“ Ixodes eudyptidis ” Heath, 1987: 22, fig. 1. Not Ixodes eudyptidis Maskell, 1885 . Ixodes eudyptidis Maskell, 1885 ; Bishop & Heath 1998: 30. In part.

“ Ixodes eudyptidis ” Heath, 2006: 133. Not Ixodes eudyptidis Maskell, 1885 . Ixodes eudyptidis Maskell, 1885 ; Heath 2010: 16. In part.

“ Ixodes eudyptidis ” Heath & Cane, 2010: 148. Not Ixodes eudyptidis Maskell, 1885 . Ixodes eudyptidis Maskell, 1885 ; Heath et al. 2011: 59. In part.

Type host: Larus novaehollandiae scopulinus J.R. Forster, 1843 .

Etymology: The species epithet “ laridis ” is a noun in apposition derived from the genus of the type host.

Material examined. Type specimens. Ex Larus novaehollandiae scopulinus [on body]: Holotype ♀ ( MONZ AA.000209), Kaikoura Peninsula [42°25'S, 173°47'E], New Zealand, 18 Nov. 1979, A.C.G. Heath . Paratypes: 2♀ [partially dissected], 2♂ [one dissected and slide-mounted], 38N [2 slide-mounted] and 7L, with same data as holotype ( MONZ AA.000210).

Ex Larus novaehollandiae scopulinus [in colony]: Paratypes 7♀, 5♂, 3L, Kaikoura, 25 Aug. 1979, A.C.G. Heath (MONZ AA.000211); 9♀, 6L, same locality, Nov. 1979, A.C.G. Heath ( MONZ AA.000212).

Non-type material from New Zealand. Ex Larus novaehollandiae scopulinus [on body]: 2♀, 3N, Christchurch, 30 Nov. 1981, Lincoln Animal Research Centre (81/8315); 2♀, Kaikoura, Nov. 1986, D. Murray ( ANIC 2080); 10♀, Lower Portobello Bay, Otago, 24 Nov. 2013, K. O'Dwyer; 7♀ (one with 7 legs, see Teratology below), Palliser Spit, no date, no collector; 2♀, Kensington Oval, Dunedin, 3 Dec. 2016, C. Cawley; 1♀, Dunedin, 15 Dec. 2016, C. Cawley; 4L reared in laboratory [slide-mounted; hatched 18 Jan. 1980, eggs from ♀, Kaikoura].

Ex Larus dominicanus Lichtenstein, 1823 [on body]: 1♀, 41N, Eastbourne, Wellington, Feb. 1978, A.G. King; 2♀, 1N, Paraparaumu Beach, Kapiti Coast, Dec. 1978, no collector; 9♀, Waikanae, Kapiti Coast, 28 Feb. 1982, A.J.D. Tennyson; 7♀ [one ♀ dissected, 2 slide mounts], 23N, 2L, Karori, Wellington, 12 Dec. 1982, P. Brownsey; 1♀ [on head], Robinson Bay, Eastbourne, 18 Nov. 1990, M. Darby; 1♀, Waikanae, Kapiti Coast, no date, per L. Hudson.

Ex Larus dominicanus : 1N [in deserted nest], Weedons Point, Chatham Islands, 5 Feb. 1980, A.C.G. Heath; 1N [under rock, near empty nest], Somes Island, Wellington Harbour, 8 Jan. 1982, A.C.G. Heath.

Ex Morus serrator (G.R. Gray, 1843) [on body]: 13N, Somes Island , Wellington Harbour, 22 Dec. 1981, R. Benfell ; 1♀ [saddle colony] Cape Kidnappers, Hawke’s Bay , 22 Dec. 1982, P. O'Brien; 3 N,>100L [2 slidemounted], Maori Bay , Muriwai Beach , Auckland, 8 Oct. 2000, E.H. Kuschel ; 1♀, Picton Wharf , 2 Dec. 2008, M. Bell.

Ex Morus serrator : 2N [in nest with one downy chick], Clova Bay , Marlborough Sounds, 30 Nov. 1981, P . O'Brien; 1♀, 2♂, 3N [under stone in rookery], landing, White Island , Bay of Plenty, 6 Dec. 1966, K .A.J. Wise (AMNZ, Reg. 120452).

Ex Stictocarbo punctatus punctatus (Sparrman, 1786) : 1♀, Eastbourne , Wellington, 26 Apr. 1977, F. Fitzgerald; 1N, Te Horo, Kapiti Coast, 30 Apr. 1977, D. Sutherland ; 2♀, 2N, 11L, Cobden Beach, Buller , 8 May 1977, T.P. Fisher ; 1♀, 4N, Somes Island , Wellington, Mar. 1984, A.C.G. Heath.

Ex Leucocarbo chalconotus (Gray, 1845) [in nest area]; 1N, Taiaroa Head , Otago Peninsula, Feb. 2007, R.P. Cane.

Ex Hydroprogne caspia (Pallas, 1770) : 3♀, Waimea Inlet , Tasman Bay, 5 Nov. 2003, G. Elliot ; 1♀, 1N, 2L, no locality, 7 Nov. 2003 (N o 35387).

Ex Sterna striata Gmelin, 1789: 2 ♀, Westport, Nov. 1983, no collector.

Ex Diomedea sanfordi Murphy, 1917: 6 ♀, 3N, 1L, Little Sister Island , Chatham Islands, 23 Nov. 1994, C.J.R. Robertson.

Ex Thalassarche bulleri platei (Reichenow, 1898) [off leg joint]: 1N, Sisters Is , Chatham Islands, 20 Nov. 1994, C.J.R. Robertson.

Ex Thalassarche eremita Murphy, 1930 [dead bird]: 5♀, Pyramid Rock , Chatham Islands, 2 December 1987, A.J.D. Tennyson.

Ex Pterodroma lessonii (Garnot, 1826) : 1N, Ohope Beach , Bay of Plenty, 7 Jan. 1971. N.R. Hellyer.

Ex Platalea regia Gould, 1838 [dead bird]: 56♀ (one with malformed scutum) [4 ♀ dissected and slidemounted on 6 slides], 10N, 1L, Waikanae Estuary, Kapiti Coast, 2 Dec. 2010, R. Mills (see Peryer & Heath 2011).

Non-type material from Australia. Ex Larus novaehollandiae novaehollandiae : 2♀, Wynyard , Tasmania, 9 Feb. 1969, R.H. Green ( ANIC) ; 2♀, 2N, 3L, Tamar River , Tasmania, 26 Sept. 1974, no collector ( ANIC 2071 , 2072 ) ; 6♀, Torquay , Victoria, 19 Aug. 1984, J. O'Mara ( ANIC 2092 ) .

Ex Morus serrator : 15N, 1L, Black Pyramid, Bass Strait , Tasmania, 27 Nov. 1961, R.H. Green ( ANIC) ; 1♀, Phillip Island , Victoria, 16 Dec. 1992, R. Norman ( ANIC 2094 ) .

Ex "albatross": 4♀, 1N, Albatross Island , Bass Strait, no date, N. Brothers ( ANIC 2076 ) ; 1♀, 2L, same locality and collector, Mar. 1986 ( ANIC 2079 ) ; 3♀, 13L, no collecting data (ANIC 2073).

Ex Tyto novaehollandiae castanops (Gould, 1837) : 1♀, Lemon Hill, Jericho , Tasmania, 21 Nov. 1960, R.H. Green ( ANIC 2091 ) ; 1♀, 1N, Campbell Town , Tasmania, 3 Aug. 1974, B. Munday ( ANIC) .

Diagnosis. A complete range of differences between I. laridis and I. eudyptidis is given in Table 1 but, in particular, the female of I. laridis is readily distinguished from that of I. eudyptidis by the smaller size, shape and reduced sculpturing of the scutum, as well as the shallow depth and reduced length of the cervical grooves ( Figs 5– 6 , 34–35 ) and the shape and number of coxal spurs. The external (distal) coxal spurs of I. laridis are triangular, and acutely pointed. Those on coxae I and II are of nearly similar size, but larger than those on III and IV, with the spur on the latter very small and about half the size of those on I and II. The external spurs on coxae of I. eudyptidis are also triangular, but I to III with rounded points, and IV more acutely pointed. The spur on I is the largest, II to III being smaller, but of approximately similar size to each other, with IV slightly smaller again.

Each species has an obvious internal (proximal) spur on coxae I, pointed in I. laridis but rounded in I. eudyptidis . In I. laridis there is no spur internally on coxae II, merely a slight, pale projection, with no similar projection on either III or IV. A pigmented border is obvious internally on coxae I to III, but only just apparent on IV. In I. eudyptidis there is a rounded projection internally on coxae II, but nothing similar on coxae III and IV, and there is no pigmented border internally on these coxae. There is no spur on trochanter IV in I. laridis females, whereas the majority of I. eudyptidis females show this feature to a greater or lesser degree (see Morphological variations.) This small spur—referred to by Nuttall & Warburton (1911: fig. 213) —is not a reliable diagnostic feature because it is sometimes absent or, when present, difficult to discern.

Other distinguishing features are the rectangular basis capituli with its lack of prominent, dorsal lateral projections, together with the shape of the porose areas in I. laridis ( Figs 1, 3 , 36 ¯37). The auriculae of I. laridis are smaller and less protuberant than in I. eudyptidis ( Figs 2, 4 , 38 ¯39) with a tendency to converge towards the palpal base, whereas those in I. eudyptidis diverge.

The shape of anal grooves also separates I. laridis from I. eudyptidis ( Figs 13–14 ). The hypostomal dentition also differs markedly in both species but is more readily seen in slide-mounted specimens. Males are also readily distinguishable with I. laridis having a longer and narrower ventral plate than I. eudyptidis , with a slightly convex posterior border versus mildly concave border in I. eudyptidis ( Figs 18, 20 , 40 ¯41). Also, males of I. laridis have both narrower and more curved adanal plates than those of I. eudyptidis , and the genital apron is smaller and narrower in I. laridis than that in I. eudyptidis . The anal plate is also narrow with a posterior notch deeper than that structure in I. eudyptidis ( Figs 18, 20 , 42 ¯43). The anterior prolongation of the epimeral plate beneath the spiracle in males of I. laridis is barely one third the depth of that in males of I. eudyptidis ( Figs 15 ¯16). Differences between the nymphs (see Table 2) are mainly in the size of some structures (e.g. length of scutum greater in I. eudyptidis ; tarsi I longer in I. laridis ; tarsi IV shorter in I. laridis ) and hypostomal dentition. In the larvae (see Table 2), the scutum in I. laridis is smaller overall than that of I. eudyptidis , and the chaetotaxy differs slightly, with I. laridis having fewer setae in some series and the main dorsal and ventral (idiosomal) body setae being considerably shorter than those in I. eudyptidis (see Table 3). Larval hypostomal dentition also differs between these two species, and the ratio of the combined length of articles 2 and 3 of the palps to the greatest width is <3 in I. laridis , whereas it is> 3 in I. eudyptidis.

Figures

FIGURES 1 – 6. Female basis capituli [without setae and hypostomal dentition]: Ixodes laridis: 1, dorsal view. 2, ventral view. Ixodes eudyptidis: 3, dorsal view. 4, ventral view. Scuta: 5, Ixodes laridis. 6, Ixodes eudyptidis.

FIGURES 7 – 10. Ixodes laridis: 7, female hypostome. 8, female tarsi (I – IV). 9, male capitulum, dorsal view. 10, male capitulum, ventral view [both without setae and hypostomal dentition].

FIGURES 11 – 16. Female spiracles: 11, Ixodes laridis. 12, Ixodes eudyptidis. Female anal grooves: 13, Ixodes laridis. 14, Ixodes eudyptidis. Male epimeral plates and spiracles: 15, Ixodes laridis. 16, Ixodes eudyptidis [only anterior portions of epimera shown. A: anterior, D: dorsal].

FIGURES 17 – 20. Males. Ixodes laridis. 17, body dorsal view. 18, body ventral view. 19, hypostome. Ixodes eudyptidis. 20, posterior region, ventral view.

FIGURES 21 – 22. Ixodes laridis coxae and trochanters (I – IV): 21, female. 22, male.

FIGURES 34 – 39. Female scuta: 34, Ixodes eudyptidis. 35, Ixodes laridis. Figs 36 – 39, capitulum: 36, Ixodes eudyptidis, dorsal view. 37, Ixodes laridis, dorsal view. 38, Ixodes eudyptidis, ventral view. 39, Ixodes laridis, ventral view.

FIGURES 40 – 45. Males, ventral views: 40, Ixodes eudyptidis. 41, Ixodes laridis. Anal and adanal plates: 42, Ixodes eudyptidis. 43, Ixodes laridis. Sternal plates (jugular, pregenital) and genital aperture: 44, Ixodes eudyptidis. 45, Ixodes laridis.