Quedius adilus, Bogri & Solodovnikov & Hansen, 2020

Hu, Fang-Shuo, Bogri, Amalia, Solodovnikov, Alexey & Hansen, Aslak Kappel, 2020, Hypogean Quedius of Taiwan and their biogeographic significance (Coleoptera: Staphylinidae: Staphylininae), European Journal of Taxonomy 664 (664), pp. 1-24 : 18-20

Quedius adilus sp. nov.

urn:lsid:zoobank.org:act:2C75AA2D-F524-4308-9823-186131633E08

Figs 2 , 3C, F , 11

Etymology The species name adilus is derived from the Greek word ‘άδηλος’, which means ‘latent’, ‘existing or

present but concealed’. This name hints at the difficulty of collecting this species, which is hidden in hypogean crevices.

Material examined

Holotype

TAIWAN • ♂; Nantou County, Yuanfeng [鳶 峰]; 6 Apr 2004 – 11 May 2004; C.S. Lin and W.T. Yang leg.; “ Malaise trap (KCN) / Quedius (Microsaurus) sp. Det. A. Brunke 2018”; “ NMNS ENT, 6660- 241 ”; NMNS.

Since the originally pinned holotype was remounted on a card in this study, its pronotal disc on the left side bears a hole from the pin. The genital segment and aedeagus were dissected and preserved in glycerin in a microvial pinned with the card. The last segment of the right antenna, as well as the middle and posterior tibiae, are missing.

Description

Male

MEASUREMENTS. HW: 2.47, HL: 2.12, HW/HL ratio: 1.17, TL/EL ratio: 7, PL: 2.54, PW: 2.83, PL/PW ratio: 0.90, A4L/A4W ratio: 1.25, total body length: 14.46, body length without terminalia: 11.05.

HABITUS. Dark brown-reddish, with paler apical part of antenna, tibia and tarsi ( Fig. 11A ). Large species, dorso-ventrally flattened, with very small eyes and long legs.

HEAD. Large, slightly wider than long, flattened and with oblique longitudinal ridge behind eyes; two basal punctures on each side (apical one is smaller) and five additional punctures near basal punctures. Antennae long and slender; antennomeres 4–10 more or less spherical.

THORAX. Pronotum distinctly narrowing anteriad; dorsal rows each with three punctures; left sublateral row with two punctures; right sublateral row with three punctures; one additional puncture between left dorsal and sublateral rows of punctures; two additional punctures between right dorsal and sublateral rows of punctures. Scutellum sparsely punctured. Elytra shorter than pronotum; hind wings absent.

LEGS. First four segments of tarsus strongly dilated.

ABDOMEN. Sternite VIII broad and sub-parallel, with distinct medial emargination apically and five setiferous punctures present at each lateral side. Sternite IX basally slightly oval, apically emarginate. Tergite X with distinct emargination basally, with several setae apically.

AEDEAGUS ( Fig. 3C, F , 11 B–C). Median lobe slightly broader than paramere, apically protruding over paramere (in parameral view), slightly sharpened apically, its subapical protrusion axe-like in lateral view; paramere large, apically bilobed, each lobe with four long apical setae and sparse sensory peg setae, apical part of paramere slightly narrower than basal part.

Female

Unknown.

Differential diagnosis

This new species is similar to Q. masuzoi and Q. nishikawai , from which it differs in the more dorsoventrally flattened head, with an oblique longitudinal ridge behind the eyes. Also, unlike both these species, Quedius adilus sp. nov. has two basal punctures on each side, instead of the usual one, and numerous (five) additional punctures near each basal puncture. Its antennomeres 4–10 are rather spherical and antennomeres 8–10 are relatively shorter than in Q. nishikawai . As these characters seem to be highly variable within this species group, reliable identification of the new species should be made through an examination of the male genitalia. Unlike in Q. masuzoi , the median lobe in Quedius adilus sp. nov. is more narrowly elongate and forms a sharper point at the apex; it strongly protrudes over the apical margin of the bilobed paramere (in parameral view) (compare Fig. 3C and 3 A–B); the elevated dents of its subapical carina are positioned more remotely from its apex (in lateral view) (compare Fig. 3F and 3 D–E). Also, compared to conditions in Q. masuzoi , the split between the apical lobes of the paramere in Quedius adilus sp. nov. is more narrow and the arrangement of the sensory peg setae is more sparse ( Fig. 11 B–C).

Distribution

Known only from the type locality in Nantou County in central Taiwan ( Fig. 2 ).

Bionomics

The holotype was collected by Malaise trap, probably accidentally. No information about the habitat is provided on the locality label.

Remarks

As established in this paper, the aedeagus shape in Q. masuzoi is stable, contrary to other characters earlier chosen to delimit that species. Therefore, the clearly visible difference in the shape of the aedeagus between Q. adilus sp. nov. and Q. masuzoi , in addition to several external characters separating the new species from Q. nishikawai , advocate for its formal description even based on the available singleton. The type locality (Yuangfeng) of the new species is only 10 km away from Nanhua Mt, the type locality of Q. masuzoi ( Fig. 2 ), which signals that the two species may be sympatric, further corroborating our hypothesis that the aedeagal difference we observe is indicative of a new species different from Q. masuzoi .

Figures

Fig. 2. Distribution of species in the Quedius abnormalis group in Taiwan. Filled square - refers to the new specimens of adults and larvae of Quedius masuzoi Watanabe, 1989 reported in this paper. Square with cross Oi is the type locality of Quedius masuzoi. Unfilled square D is the type locality of Quedius chiangi Smetana, 1995, junior synonym of Q. masuzoi. Question mark (?) refers to an undescribed female specimen reported in Watanabe (1989). Unfilled circle O is the type locality of Quedius nishikawai Watanabe, 1991. Filled star * is the type locality of Quedius adilus sp. nov.

Fig. 3. Aedeagi and female terminalia of species of the Quedius abnormalis group from Taiwan. The graphic symbol on each illustration refers to the collection locality on Fig. 2 as follows: filled square - to the new specimens of Quedius masuzoi Watanabe, 1989 reported in this paper; square with cross Oi to the male holotype of Quedius masuzoi; unfilled square D to the female holotype of Quedius chiangi Smetana, 1995, synonym of Q. masuzoi; unfilled circle O to the female holotype of Quedius nishikawai Watanabe, 1991; filled star * to the male holotype of Quedius adilus sp. nov. Top row (A–C): parameral view of aedeagus. Middle row (D–F): lateral view of aedeagus. Bottom row (G–I): female tergite X. Scale bars = 0.5 mm.

Fig. 11. Quedius adilus sp. nov. A. Habitus, legs and antennae of left side cropped out of image to preserve space. B. Aedeagus in lateral view. C. Aedeagus in parameral view. Scale bar: A = 1 mm.