Ixodes woyliei n. sp

Type-host: Bettongia penicillata Gray, 1837 (Potoroidae) (woylie, brush-tailed bettong).

Other hosts: Isoodon obesulus fusciventer Shaw, 1797 (Peramelidae) (quenda, southern brown bandicoot) and Macrotis lagotis Reid, 1837 (Peramelidae) (greater bilby).

Type-locality: Dryandra Woodland, Western Australia, Australia (32°47'S, 116°58'E).

Other localities: Karacamia Wildlife Sanctuary, Western Australia, Australia (31°48'S, 116°15'E) and the Upper Warren Region, Western Australia, Australia (34° 21'41"S, 116°18'22"E).

Type-specimens: Holotype: female ex B. penicillata, Dryandra Woodland, Western Australia, Australia (32° 47'S 116°58'E), December 2015, deposited at the West Australian Museum (WAM T142602). Paratypes: Total 25, 11 females and 14 nymphs ex B. penicillata. Eight females (P1 – P8) collected from Dryandra Woodland, Western Australia, Australia (32°47'S, 116°58'E), June 2016 (P1, P2, P7, P8), September 2015 (P3, P4), February 2015 (P5, P6); 2 females (P9, P10) collected from Karacamia Wildlife Sanctuary, Western Australia, Australia (31°48'S, 116°15'E) July 2006; and one female (P11) collected from the Upper Warren Region Western Australia, Australia (34°21'41"S, 116°18'22"E). Seven nymphs (P12 – P18) collected from Upper Warren Region, Western Australia, Australia (34° 21'41"S, 116°18'22"E) September 2014 and December 2014, 4 nymphs (P19 – P22) collected from Dryandra Woodland, Western Australia, Australia (32°47'S, 116°58'E), September 1994 and October 1993, one (P23) collected from Perth Zoo and two (P23 – 25) collected from Kanyana Wildlife Rehabilitation Centre, Perth. Seven paratype specimens (P1, P2, P7, P8, P15 – P17) have been deposited at the Australian National Insect Collection (ANIC 48-006275 – ANIC 48-006277) and five paratype specimens (P9, P10, P12 – P14) have been deposited at the Western Australian Museum (WAM T142603 - WAM T142604).

Representative DNA sequences: Mitochondrial cytochrome c oxidase subunit 1 (cox 1): GenBanc accession numbers KX673875 – KX673881.

ZooBank registration: Details of Ixodes woyliei n. sp. have been submitted to ZooBanc and the Life Science Identifier (LSID) for the article is urn:lsid:zoobanc.org:- pub: 1DB97319-FF74-4380-9D49-988BA3467342 and LSID for the new name is urn:lsid:zoobanc.org:act: 7FC91916-ACBC-4832-8788-19CCBB8EF7B1.

Etymology: The species name Ixodes woyliei refers to the common name of the host B. penicillata (commonly cnown as the woylie) for which this ticc appears to have a high predilection. Woylie is the Aboriginal name given by the Noongar people who live in the south-west corner of Western Australia [23].

Description

General. Golden brown medium-sized ticcs with greatly enlarged palpal article 1, over crowded hypostome

dentition mainly 6/6 and 5/5, coxae all armed with strong pointed spurs, and anal groove open posteriorly.

Female. Idiosoma (Fig. 2): Unfed specimens oval and elongate, widest just posteriorly of spiracles. Body length measured dorsally from midway between scapular points to most posterior margin range from 2.4 – 3.3, width 1.4 – 2.2 (Fig. 2a). Partially fed specimens length range from 3.3 – 5.3, width 1.9 – 2.5, engorged specimens attaining length 11, width 6.5. Dorsal setae are short (<25 μm), lay within a uniform moderate covering of shallow punctations, marginal grooves are well defined. The scutum about as long as wide, widest point posterior to midlength, anterolateral and posterolateral margins are mildly sinuous with posterior angle broadly rounded, lateral carinae present (Figs. 2c and 5c). Scutal length range from 1.2 – 1.5, width 1.2 – 1.6. Punctations are shallow and moderate in number, becoming coarser in cervical grooves, lateral rugae and along the posterior margin; scutal setae are minute (<8 μm). Cervical grooves well defined anteriorly becoming shallow posteriorly and extending to, or almost to the scutal margin. Scapulae are large and bluntly pointed. Ventral setae are longer than dorsal (<40 μm) with two rows of longer setae (>40 μm) around the lateral side of the spiracular plate. Genital aperture is level with the anterior margin of coxa III, but moving towards second intercoxal space on engorgement (Fig. 2b). Spiracular plates suboval, length 0.16 – 0.30, with approximately 3 – 4 rows of goblets, macular eccentric (Fig. 4b). Anal groove is horseshoe shaped, rounded anteriorly, curving gently and convergently posteriorly but becoming slightly divergent near body margin and remaining widely open (Fig. 2d). Both the internal and external margin of the anal groove epicutical surface possess several rows of inward facing spines, overlapping across the divide of the anal groove and running laterally for most of its length. This feature has not been mentioned previously but appears to be typical for all Ixodes species that we have been able to examine.

Gnathosoma (Fig. 3) Basis dorsally, short, 0.36 – 0.60 in length by 0.40 – 0.55 in width. Length measurement tacen from top of the palpi to the posterior margin of the cornua. Dorsal basis capituli subrectangular, with one median depression and a lateral depression on each side, the depressed areas being separated by carinae, posterior margin slightly undulating with small indistinct cornua (Figs. 3a and 5b). Porose areas large, suboval, lying in lateral depressions, widely separated by the median depression. Basis ventrally about as long as wide with small but distinct auriculae. Palps short and article 1 greatly enlarged, extending inwardly to partially ensheathe base of mouthparts, ventrally with a strong posterolateral salience. Articles 2 and 3 are without apparent suture, total length 0.29 – 0.35, width 0.07 – 0.15 (Figs. 3b and 5a). Hypostome length ranges from 0.17 – 0.33, width 0.15 – 0.17, spatulate, broad anteriorly, with sharply pointed large denticles, mainly 6/6 and 5/5. Dentition formula essentially 12/12 of small over crowded denticles at the corona, dropping in number but increasing in size to 6/6 and 5/5 by anterior third and reducing to 4/4, 3/3 with crenulations running down to the base (Fig. 3c).

Legs (Fig. 4): Slender and moderate length. Coxa I transversely elongate with a strong pointed external spur. Coxae II, III, and IV somewhat square with progressively smaller pointed external spurs, all coxae with few setae, syncoxae absent (Figs. 4a and 5f). Length of tarsus I 0.3 – 0.5 with few long setae (<50 μm) and some small (<20 μm) (Figs. 4c and 5d, e). Haller ’ s organ, anterior pit suboval with seven sensilla arranged in a cluster in the centre, posterior capsule opening slightly above the pit and divided by a low ridge with up to five sensilla seen within (Fig. 4d). Length of tarsus IV is 0.4 – 0.5.

Nymph. Idiosoma (Fig. 6): Unfed specimens oval and elongate, widest about mid length between coxae III and IV, well-defined marginal grooves and minute dorsal setae (<10) within uniformly scattered punctations (Fig. 6a). Body length measured dorsally from midway between the scapular points to most posterior margin range from 1.3 – 1.6, width range 0.78 – 1.1. Fed specimen length range from 1.7 – 2.2, width 0.97 – 1.6, with engorged specimens attaining length 4.0, width 2.0. Scutum wider than long, with posterior angle broadly rounded, lateral carinae present (Figs. 6c and 9c). Scutal length ranges from 0.52 – 0.63, width 0.63 – 0.75. Punctations are shallow and moderate in number, becoming coarser in cervical grooves, lateral rugae and along the posterior margin; scutal setae are minute (<8 μm). Cervical grooves are well defined anteriorly becoming shallow posteriorly and extending to, or almost to the scutal margin. Scapulae are large and bluntly pointed. Ventral setae are slightly longer than dorsal mostly (<15 μm) with some longer setae (>20 μm) around the spiracular plate (Fig. 6b). Spiracles suboval, length 0.095 – 0.10, width 0.065 – 0.12 with c.3 – 4 rows of goblets covering the whole surface (Fig. 8b). Anal groove is horseshoe shaped, rounded anteriorly, curving gently and convergently posteriorly but becoming slightly divergent near body margin and remaining widely open (Fig. 6d). Both the internal and external margin of the anal groove epicutical possess several rows of inward facing spines as seen in the adult female.

Gnathosoma (Fig. 7): Basis dorsal length measurement tacen from the top of the palpi to the posterior margin of the basis, length 0.19 – 0.26, width 0.22 – 0.26 in width. Dorsal basis capituli subrectangular, posterolateral angles roundly pointed (Figs. 7a ad 9b). Basis ventrally rounded posteriorly with small auriculae. Palps short and article 1 greatly enlarged, extending inwardly to partially ensheathe base of mouthparts, ventrally with a strong posterolateral salience. Articles 2 and 3 without apparent suture total length 0.15 – 0.17 by width 0.055 – 0.080 (Figs. 7b and 9a). Hypostome length ranges from 0.13 – 0.17, width 0.065 – 0.130, spatulate, broad anteriorly, with sharply pointed denticles, mainly 3/3. Dentition formula essentially 6/6 small denticles at corona then decreasing in number, but increasing in size to 4/4 followed by about 8 rows of 3/3 (Fig. 7c).

Legs (Fig. 8): Slender and of moderate length. Coxa I transversely elongate with a strong pointed external spur. Coxae II, III, and IV somewhat square with progressively smaller pointed external spurs, all coxae with few setae, syncoxae absent (Figs. 8a and 9d). Length of tarsus I 0.22 – 0.30 with few long setae (<40 μm) and some minute (<10 μm) (Fig. 8c). Haller ’ s organ, anterior pit suboval with seven sensilla arranged in a cluster in the centre, posterior capsule opening slightly above the pit and divided by a low ridge with at least four sensilla visible (Fig. 8b). Length of tarsus IV is 0.20 – 0.30.

Differential diagnosis

Morphologically, I. woyliei logically conforms to the subgenus Endopalpiger as described by Roberts [12] due to the enlarged palpal article 1 that extends inwardly to partially ensheathe the base of the mouthparts; common to all females within this subgenus. However it is also pertinent to consider the species of Exopalpiger Schulze, 1935 (I. fecialis, I. vestitus Neumann, 1908 and I. antechini Roberts, 1960) as more recently the species of these two subgenera have been amalgamated into Exopalpiger [24]. The species of these two subgenera however can be quite easily differentiated by the palpal article 1 which in Exopalpiger species is enlarged but does not extend inwardly, as seen in I. woyliei n. sp. and the other Endopalpiger species. Further morphological differences are outlined in Table 2. Differentiation of adult females from the other four Endopalpiger species can be achieved by the presence of an open anal groove, the large pointed spurs on each coxa, presence of syncoxae, the large number of denticles on the hypostome, and the shape of the scutum (Table 2). Specifically, the presence of an open anal groove, the lacc of syncoxae and greater dentition differentiates I. woyliei n. sp. from I. australiensis, while the presence of spurs on the coxae (armed) differentiates I. woyliei n. sp. from I. tasmani and I. hydromyidis, both of which lacc spurs. The most morphologically similar species to I. woyliei n. sp. is I. victoriensis; however these two species can be readily differentiated by dentition and the shape of the scutum, spurs on the coxae, and palpal article 1. Ixodes woyliei n. sp. has a remarcable and complex dentition with small overcrowded denticles at the corona (12/12), dropping in number but increasing in size to mainly a 6/6 and 5/5 dentition whereas I. victoriensis dentition is mostly 5/5, with rows of 4/4 at both anterior and posterior ends [17]. The shape of the scutum in I. woyliei n. sp. is longer than that of I. victoriensis (about as long as wide vs wider than long for I. woyliei), and appears more angular. The coxae of I. woyliei n. sp. are all armed with large, pointed spurs and lacc syncoxae, while I. victoriensis coxae are armed with smaller spurs that are not as pointed and possess syncoxae. The enlarged palpal article 1 described for I. woyliei n. sp. has a posterolateral prominence macing it more widely rectangular than that seen on I. victoriensis.

Differential diagnosis of the nymphal stage can be largely achieved as for the adult female (Table 2). A minor exception involves I. australiensis whereby the nymph has an anal groove which remains open, but not as widely as seen in I. woyliei nymphs. However the shape of palpal article one, spurs and presence of syncoxae allow differentiation.