Ixodes nipponrhinolophi Hornok & Takano sp. nov.

Figs 2, 3

Diagnosis.

Medium size (female 4 mm long) brown tick. Legs and palps long. Scutum posteriorly broad, rounded, with moderately deep cervical grooves and pits. Hair covering dense both dorsally and ventrally. Coxae without spurs, coxae I and II with straight and III and IV with semicircular medial edges. Spiracular plates subcircular.

Material examined.

Holotype: female, from Rhinolophus cornutus Temminck, Japan, Yamaguchi, Mine city, 34.251084°N, 131.243056°E (DD), 25 February 2021, A. Takano coll. Paratypes: five females. (1): from Rhinolophus ferrumequinum (Schreber), Japan, Kumamoto, Kuma-gun, 32.252183°N, 130.651239°E (DD), 24 December 1973, K. Funakoshi coll. (2) : female, from Rhinolophus ferrumequinum, Japan, Kumamoto, Kuma-gun, 32.252183°N, 130.651239°E (DD), 12 April 1979, K. Funakoshi coll. (3) : female, from Rhinolophus ferrumequinum, Japan, Kumamoto, Kuma-gun, 32.252183°N, 130.651239°E (DD), 10 May 1979, K. Funakoshi coll. (4) : female, from Rhinolophus ferrumequinum, Japan, Kumamoto, Kuma-gun, 32.252183°N, 130.651239°E (DD), 25 May 1979, K. Funakoshi coll. (5) : female, from Rhinolophus cornutus, Japan, Gunma, Tano-gun, 36.086915°N, 138.721945°E (DD), 23 April 2005, M. Takahashi coll.

Morphology of female (holotype, unengorged).

Length of the idiosoma (from the half point between scapular apices to the middle of posterior margin) 3.18, width 1.74, ratio of idiosomal length/width 1.83 (Suppl. material 2: fig. 1A).

Scutum elongated, tie-shaped, broadest near posterior third. Deepest point of concavity at anterior third of length (Fig. 2C - 1). Length of scutum 1.62, maximum width 0.99, ratio of length/width 1.64. Scutum with cervical grooves deep, narrow in second quarter of length (Fig. 2C-2); scattered, small punctuations; and two pits close to its maximum width (Fig. 2C - 3). Posterolateral edge (after maximum width) convex. Scutal setae few, close to scapulae 0.03 long.

Alloscutum with dense hair covering dorsally. Length of centrodorsal setae 0.1, marginodorsal setae 0.16. Idiosoma has dense hair covering ventrally. Genital aperture broad U-shaped, with nearly parallel end (Fig. 2D - 1), slightly posterior to 2nd-to-3rd intercoxal space. Genital groove posteriorly converging, then diverging (Fig. 2D-2), bowling pin-shaped (Suppl. material 2: fig. 1B). Spiracular plates subcircular, diameter 0.44, aeropyles randomly distributed, width of aeropyle rows (minimum to maximum) 2:7; position of spiracle opening submarginal, rounded, diameter 0.06 (Suppl. material 2: fig. 1C). Anal valves with 4-4 setae, arranged in C-shaped curve (Suppl. material 2: fig. 1D). Anal groove slightly converging (Suppl. material 2: fig. 1B).

Length of gnathosoma (from palpal apices to posterior margin of basis capituli) 0.84, width of basis capituli dorsally 0.63. Ratio of gnathosomal length/basis capituli width 1.33. Basis capituli triangular, its sides anteriorly converging, broadest at lateral ridge continuing ventrally (Fig. 2A - 1), posteriorly as broad as at maximum width of palpal base, without cornuae; posterior margin dark, sclerotised, nearly linear. Shape of areae porosae triangular anteriorly, broad posteriorly (Fig. 2A-2), with short, low lateral ridge (Fig. 2A - 3). Ventrally the basis capituli triangular anterior to maximum width, reverse trapezoidal posteriorly, with squared concavity in between. Auriculae absent (Fig. 2B - 1).

Palps (dorsal view) long, club-shaped, length 0.7, broadest anterior to junction of segments II and III, maximum width 0.17, ratio of length/width 4.1. Palpal hairs 0.03-0.08, longest medially on palpal segment II. Palpal segment I. 0.08, palpal segment II. 0.4, palpal segment III. 0.23 long. Ratio of palpal segments II/III 1.8, segment II 2.8 × longer than broad when viewed vertically; its “stalk” with surface in level with that of broad part (Fig. 2A - 4).

Hypostome lanceolate, anterior tapering straight, apex pointed. Length 0.4, width 0.18, ratio of length/width 2.2. Dental formula 3/3 (mid-length), apically 4/4 or more. Teeth posteriorly long (0.06), slender, elevated (Fig. 2B-2).

Legs long and slender. All coxae marginally dark (sclerotised), without spines or spurs. Coxa I trapezoid, with minute hairs (posteriorly 0.05). Coxa II rectangular, medial edge straight (Fig. 2D - 3), posteriorly wrinkled, posterolateral hairs short (0.1). Coxa III semicircular (Fig. 2D - 4), hairs 0.03-0.07. Coxa IV semicircular, hairs 0.05. Tarsus I with long setae (<0.25) dorsally, length 1.3, maximum diameter 0.15, ratio of length/diameter 8.7. Haller’s organ elongated, with grouped (non-linear) anterior pit sensillae, one of them longer (0.04).

Differential diagnosis.

Ixodes nipponrhinolophi Hornok & Takano, sp. nov. is easily distinguished from members of the Ixodes simplex complex based on the long legs, and from members of the Ixodes ariadnae complex according to its long palps. Within the Ixodes vespertilionis complex, differences in comparison with females of the most similar species, Ixodes collaris include the following characters of the latter. Anteriolaterally on the scutum, the deepest point of concavity is at the anterior 1/8 of its length (Fig. 3C - 1); cervical grooves broad (Fig. 3C - 2), there are no pits; punctuations dense, especially anteriolaterally, (Fig. 3C-3). Genital aperture horizontally C-shaped, with diverging end (Fig. 3D - 1), between third coxae, genital groove posteriorly diverging (Fig. 2D-2; Suppl. material 3: fig. 2B). Spiracle opening elongated, diameter 0.1 (Suppl. material 4: fig. 3C). Anal groove parallel behind the anus (Suppl. material 3: fig. 2D). Basis capituli posteriorly with transverse ridge, continuing laterally then ventrally as broad “collar” (Fig. 3A - 1); shape of areae porosae elongated, tapering both anteriorly and posteriorly (Fig. 3A - 2), their border well-defined, elevated laterally as diverging, then converging high ridge (Fig. 3A-3). Ventrally collar broad, extending above first coxae parallel with their surface (Fig. 3B - 1), unlike in I. nipponrhinolophi Hornok & Takano, sp. nov. Ratio of palpal segments II to III 1.6, segment II only 2.1-times longer than broad when viewed vertically; its broad part with surface elevated above that of “stalk” (Fig. 3A - 4). Hypostome teeth posteriorly less elevated (Fig. 3B - 2). Medial edge of coxa II slightly curved (Fig. 3D-3), of coxa III straight (Fig. 3D - 4).

Gene sequences.

The complete mitochondrial genome sequence was deposited in GenBank (LC769935). All accession numbers relevant to the new species are listed in Suppl. material 1.

Host records.

Known host species: Rhinolophus cornutus, Rhinolophus ferrumequinum .

Etymology.

The name of the new species refers to Japan (in Japanese: Nippon), where all specimens have been collected, and to the type host family of horseshoe bats, Rhinolophidae .