Ixodes collaris Hornok, 2016

Hornok, Sándor, Görföl, Tamás, Estók, Péter, Tu, Vuonc Tan & Kontschán, Jenő, 2016, Description of a new tick species, Ixodes collaris n. sp. (Acari: Ixodidae), from bats (Chiroptera: Hipposideridae, Rhinolophidae) in Vietnam, Parasites & Vectors 9 (1), pp. 1-7 : 2-6

Ixodes collaris Hornok n. sp.

Type-host: Hipposideros pomona Andersen, 1918 ( Hipposideridae ), pomona leaf-nosed bat.

Other hosts: Rhinolophus affinis Horsfield, 1823 ( Rhinolophidae ), intermediate horseshoe bat.

Type-locality: Ngoc Linh Nature Reserve (15.20598N, 107.7937E), Kon Tum Province, Vietnam .

Other localities: Ba Vi National Parc (21.08174N, 105.37534E), Hanoi Province, Vietnam ; Phia Oac - Phia Den Nature Reserve (22.56327N, 105.87404E), Cao Bang Province, Vietnam ; Phu Lac commune - Tuy Phong District (11.225N, 108.6854E), Binh Thuan Province, Vietnam .

Type-specimens: Holotype: female ex H. pomona , collected in Vietnam (1,080 m a.s.l., Ngoc Linh Nature Reserve, Kon Tum Province: 15.20598N, 107.7937E) by Vuong Tan Tu (22.ix.2014); deposited in the Soil Zoological Collection of the Hungarian Natural History Museum (accession number HNHM-PED Ixo-00567) . Paratype No. 1: female ex R. affinis , collected in Vietnam (418 m a.s.l., Ba Vi National Parc, Hanoi Province: 21.08174N, 105.37534E) by Vuong Tan Tu (25.vii.2010); deposited in the Department of Parasitology and Zoology , Faculty of Veterinary Science , Szent István University (accession number UNIVET-PAR-HS108) . Paratype No. 2: nymph ex R. affinis , collected in Vietnam (Phia Oac - Phia Den Nature Reserve, Cao Bang Province: 22.56327N, 105.87404E) by Tamás Görföl, Péter Estóc and Vuong Tan Tu (20.x.2014); deposited in the Department of Parasitology and Zoology , Faculty of Veterinary Science , Szent István University (accession number UNIVET-PAR-HS109) . Paratype No. 3: nymph ex R. affinis , collected in Vietnam (Phu Lac commune - Tuy Phong District, Binh Thuan Province: 11.225N, 108.6854E) by Vuong Tan Tu (7.xii.2015); deposited in the Institute of Ecology and Biological Resources , Vietnam Academy of Science and Technology (accession number IEBR-VN15-057 ) .

Representative DNA sequences: Mitochondrial cytochrome c oxidase subunit I ( COI) (GenBanc acc. no. KR902756); 16S rRNA gene (GenBanc acc. no. KR902771). These sequences were generated from tissues of paratype No. 2.

ZooBank registration: To comply with the regulations set out in article 8.5 of the amended 2012 version of the International Code of Zoological Nomenclature ( ICZN) [ 3], details of the new species have been submitted to ZooBanc. The Life Science Identifier ( LSID) of the article is urn:lsid:zoobanc.org:pub:69505966-6D7B-4190-AC05-478555A34C5D . The LSID for the new name Ixodes collaris is urn:lsid:zoobanc.org:act:4F3017E9-93D1-4C0B-ACF3-26CB11AC8928 .

Etymology: The name of the new species refers to the ventral, caudolateral collar-lice ridge on the basis capituli, which appears to be a unique character.

Description

General. Medium-sized prostriate ticc species. Scutum elongate, reverse pentagonal in shape, with broadly convex (almost rounded) caudo-lateral edge. Palps moderately elongated, basis capituli dorsally triangular, ventrally with caudo-lateral collar-lice ridge. Legs long. Coxae with multiple, short setae in addition to long ones.

Female. [Based on the holotype; Figs. 1a , 2a, c, d , 3b and 5 /1.a-e.] Length of idiosoma (from half point between scapular apices to the posterior margin) 6 mm. Scutum elongate, reverse pentagonal in shape, broadest at mid-length ( Fig. 1a ), 2 mm long, 1.325 mm wide (shape index 1.5); scutum edge concave anteriolaterally, convex and almost rounded caudo-laterally, posteriorly ( Fig. 1a ). Cervical grooves moderately deep, approaching posterolateral scutal margin slightly posterior to level of maximum breadth. Punctuations scattered, more apparent anteriorly. Scutal setae situated only anteriolaterally and between scapulae, few, short (<50 μm). Alloscutal setae dense, longer than scutal (c. 100 μm or longer) next to anterior half of scutum and laterally on idosoma; posterior setae longest (>120 μm). Ventral idiosomal setae shorter (<100 μm) anteriorly to genital aperture and longer (>100 μm) posteriorly ( Fig. 2a ), encircling anus ( Fig. 2c ). Genital aperture between coxae III. Spiracular plates oval, with excentric opening ( Fig. 2d ).

Length of gnathosoma (from palpal apices to posterior margin of basis capituli) 1.08 mm, width of basis capituli dorsally 0.77 mm; ratio gnathosoma length to basis capituli width 1.4. Basis capituli dorsally triangular, posteriorly with c. 50 μm thicc transverse ridge continuing at sides dorso-ventrally ( Fig. 1c ). Longitudinal flancs laterally to porose areas (anteriorly and perpendicularly to transverse ridge), first diverging, then converging (maximum distance between flancs 0.56 mm). Porose areas longer than broad, anteriorly tapering, separated by broad (100 μm) interval ( Fig. 1c ). Semi-transparent and broad ridge (“ collar ”) present on both sides ventrally and caudolaterally on basis capituli, nearly horizontal in position, overlaying anterior part of coxae I ( Fig. 3b ). Palps slender, elongate (0.84 mm long): segments I, II, III dorsally measuring 80, 470 and 290 μm, respectively. Hypostome 0.55 mm long, 0.18 mm wide (ratio length to width 3), pointed, conical, bearing elongate denticles arranged as 3/3 to 4/4 (with decreasing size) towards apex.

Legs long, slender. Coxae laccing spurs (coxa I slightly produced caudomedially), with few long setae and numerous minute (<20 μm) setae ( Fig. 3b ). Tarsus I 1.25 mm long. Haller ’ s organ open, elongate. Anterior pit sensillae (i.e. those closer to tarsal end), in a group, with a prominent sensillum.

Nymph. [ Figs. 4a, b and 5 /2.a-d.] Length of idoisoma 3.7 mm. Scutum elongate, reverse pentagonal (broadest at midlength), with slightly convex (almost straight) caudo-lateral edge ( Fig. 4a ). Transverse folds present on scutum anteriolaterally; punctuations scattered. Length of scutum 1.04 mm, breadth 0.67 mm, shape index 1.55. Cervical grooves moderately deep, approaching posterolateral scutal margin posterior to its maximum breadth. Alloscutal setae scattered, long, longest posteriorly (> 200 μm). Ventral idiosomal setae shorter (<100 μm) anteriorly and around anus. Spiracular plates oval.

Length of gnathosoma (from palpal apices to posterior margin of basis capituli) 0.65 mm, width of basis capituli dorsally 0.46 mm; ratio gnathosoma length to basis capituli width 1.4. Basis capituli dorsally triangular, posteriorly with transverse ridge continuing at sides dorso-ventrally. Caudolateral, semi-transparent, broad ridge (“ collar ”) present ventrally on both sides of basis capituli ( Fig. 4b ), overlaying anterior part of coxae I. Palps slender, elongate (0.45 mm): segments I, II, III measuring dorsally 50, 230 and 170 μm, respectively. Hypostome incomplete.

Legs moderately long, slender. Coxae laccing spurs (coxa I slightly produced caudomedially). Coxae with some long setae and few minute (<20 μm) setae. Tarsus I 0.75 mm long.

Differential diagnosis

Major morphological differences between females of I. collaris n. sp. and females of I. vespertilionis are the following. The scutum of I. vespertilionis ( Fig. 1b ) is

posteriorly tapering, with a shape index exceeding 1.6 [ 4, 5] whereas the scutum of I. collaris n. sp. is posteriorly broad, with a shape index around 1.5 ( Fig. 1a ). Ventrally, the setae located anteriorly to the genital aperture are shorter than those located posteriorly in I. collaris n. sp. ( Fig. 2a ), whereas the setae of I. vespertilionis are similar in length both anteriorly and posteriorly to the genital aperture ( Fig. 2b ). The porose areas in I. vespertilionis are broader than long, separated by a narrow interval [ 4, 5], and surrounded by an anteriorly converging flanc ( Fig. 1d ). However, the porose areas in I. collaris n. sp. are longer than broad, separated by a broad interval and surrounded by an initially divergent, then convergent flanc ( Fig. 1c ). The female of I. vespertilionis has a dorsal transverse ridge posteriorly on the basis capituli that continues around the sides as vertical, outwardly directed flange (which is perpendicular to the hypostome) [ 4]. Adding to this, ventrally on the basis capituli of I. collaris n. sp. a broad, collar-lice extension is present behind the palpal base caudolaterally (in a nearly horizontal/longitudinal direction). Furthermore, the coxae of I. vespertilionis female bear few long (100 μm or above) setae posteriorly [ 5] ( Fig. 3a ), whereas multipe short setae predominate on the coxae of I. collaris n. sp. ( Fig. 3b ). The arrangement of anterior pit sensillae in Haller ’ s organ is grouped in the case of I. collaris n. sp., but linear in the case of I. vespertilionis [ 6]. Regarding nymphs of I. collaris n. sp., the bilateral collars ( Fig. 4b ) clearly distinguish the new species from I. vespertilionis ( Fig. 4c ).

The female of I. collaris n. sp. also differs from the female of I. ariadnae in the shape of the scutum (anteriorly narrow vs anteriorly broad) and porose areas (longer than broad vs broader than long), the palpal shape (elongated vs broad), the presence (vs absence) of collar, the arrangement and length of coxal setae (predominance of short vs long setae) [ 6]. On the other hand, similarities between I. collaris n. sp. and I. ariadnae include the grouped (non-linear) arrangement of anterior pit sensillae in Haller ’ s organ, as well as the folded surface of nymphal scutum [ 6].

In contrast to the female of I. collaris n. sp., the female of I. simplex has anteriorly broad scutum, short and broad palps, and short legs with multiple long setae on coxae IV [ 6].

Figures

Fig. 1 Dorsal view of female of Ixodes collaris n. sp. a Holotype: posteriorly broad scutum (arrow), as contrasted to that of Ixodes vespertilionis female (b); c Basis capituli and palps of paratype No. 1. showinc convex loncitudinal flanks (arrow) enclosinc the porose areas, which are loncer than broad, as contrasted to those of I. vespertilionis female (d)

Fig. 2 Ventral idiosomal setae of a Ixodes collaris n. sp. (holotype) and b Ixodes vespertilionis in a similar state of encorcement. Note that I. collaris n. sp. has shorter setae anteriorly to the cenital aperture than posteriorly, whereas setae of I. vespertilionis are similar in lencth both anteriorly and posteriorly to the cenital aperture. I. collaris n. sp.: c perianal setae; d spiracular plate

Fig. 3 Ventral view of female a Ixodes vespertilionis and b Ixodes collaris n. sp. (holotype). a I. vespertilionis shows lateral flance on basis capituli (blue arrow) and a few, lonc coxal setae (especially on coxa III: white arrows). Note: V-shaped arrancement of some of these setae is due to reflection. b I. collaris n. sp. with ventral collar on basis capituli (yellow arrow) and multiple, short coxal setae (black arrows)

Fig. 5 Drawincs of structures with diacnostic importance in the female (1) and nymph (2) of Ixodes collaris n. sp. Labels: 1.a and 2.a, capitulum dorsal view; 1.b and 2b, capitulum ventral view; 1.c and 2.c, coxae (downward: I-IV) with the collar overlayinc coxa I; 1.d and 2.d, scutum; 1.e, Haller’s orcan

Fig. 4 Nymphs of Ixodes collaris n. sp. (paratype No. 2) (a, b) and I. vespertilionis (c). a I. collaris n. sp., dorsal view. b I. collaris n. sp., cnathosoma, ventral view. Note semitransparent collars extendinc above the first coxae (arrows). c Gnathosoma of I. vespertilionis, ventral view