Chydaeus gutangensis Kataev & Liang
Kataev, Boris M., Liang, Hongbin & Kavanaugh, David H., 2012, Contribution to knowledge of the genus Chydaeus in Xizang Autonomous Region [Tibet] and Yunnan Province, China (Coleoptera, Carabidae, Harpalini), ZooKeys 171, pp. 39-92: 46-49
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|Chydaeus gutangensis Kataev & Liang|
Holotype, a male, deposited in IOZ, labeled: " China, Xizang Autonomous Region, Medog Co., Gutang Township, 2000 m, 16.X.1982, Han Yinheng leg."
(male). Dorsal habitus as in Fig. 52 View Figures 51–55 . Size: Body length 9.3 mm, width 4.0 mm.
Color: Body black, slightly shiny on dorsum, almost matte due to fine micropunctation and distinct, granulate microsculpture; two penultimate abdominal sterna V and VI along posterior margin and sternum VII (anal) in apical portion clearly paler, light brown. Antennae, palpi, and legs light brown, femora slightly infuscated.
Microsculpture: Head with dorsal microsculpture distinct throughout, comprised of very distinct, isodiametric, almost granulate meshes. Pronotum with microsculpture distinct throughout, comprised of distinct isodiametric and slightly transverse meshes. Elytra with microsculpture distinct throughout, comprised of isodiametric meshes, granulate on three lateral intervals.
Head: Comparatively large (HWmax/PWmax = 0.70 and HWmin/PWmax = 0.59), covered with micropunctures and very fine wrinkles on dorsum; tempora short, slightly convex. Clypeus slightly depressed laterally and apically, with apical margin slightly concave and unbordered. Frontal suture superficial. Frontal foveae moderately wide and shallow, clypeo-ocular prolongations short and faintly impressed. Supraorbital setae situated at level of hind margins of eyes. Eyes slightly convex. Antennae short [apical antennomeres missing], with antennomeres 5 to 7 each about 1.8-2.0 times as long as wide. Labrum distinctly emarginate apically. Left mandible blunt at apex. Apex of ligular sclerite concave, with apical angles slightly projected laterally.
Pronotum ( Fig. 16 View Figures 16–22 ): Relatively long (PWmax/PL = 1.36), distinctly narrowed basad (PWmax/PWmin =1.27) and widest in anterior third. Sides gently rounded anteriorly, moderately sinuate in basal half and slightly divergent just before base; each side with one lateral setigerous pore in anterior third. Apical margin almost straight, bordered only near apical angles. Basal margin slightly emarginate medially, slightly oblique laterally, faintly bordered throughout, very slightly wider than apical margin and slightly narrower than elytral base between humeral angles. Apical angles acute, distinctly but not markedly produced anteriad. Basal angles almost 90°, with sharp apices, not denticulate. Pronotal disc moderately convex, not depressed basally, moderately sloped to sides and abruptly sloped to apical angles. Lateral depressions narrow anteriorly, slightly widened behind middle and indistinct at basal angles. Basal foveae wide and very shallow. Area at basal angles flat. Pronotal surface throughout densely micropunctate and covered with very fine wrinkles; laterobasal areas slightly more coarsely punctate.
Elytra: Oval, gradually rounded at sides, moderately wide (EL/EW= 1.40, EL/PL = 2.38, EW/PWmax = 1.25), widest at middle and fused along suture. Humeri rounded, without denticles at apices. Subapical sinuations very shallow. Sutural angles acute, sharp at apices, not separated from each other. Basal borders markedly sinuate, joined with lateral margin at an acute angle. Striae superficial, very fine, impunctate, slightly crenulate; inner striae nearly effaced at apex. Parascutellar striae rudimentary, each with a basal setigerous pore. Intervals absolutely flat, impunctate. Umbilicate setal series without distinct gap medially.
Hindwings: Reduced to small scales.
Venter: Prosternum finely punctate and pubescent. Medial prosternal process prominent and projected posteriad ( Fig. 18 View Figures 16–22 ). Proepisterna smooth. Metepisterna ( Fig. 17 View Figures 16–22 ) distinctly wider than long and slightly narrowed posteriad. Sternum VII (anal) with two pairs of setae along apical margin, rounded at apex.
Legs: Metacoxae ( Fig. 19 View Figures 16–22 ) with posteromedial setigerous pore and without additional, setigerous or non-setigerous foveae medially. Metafemora with two setae along posterior margin. Protibiae with one preapical spine at outer distal margin and one ventroapical spine. Tarsi distinctly setose dorsally, tarsomere 5 with three pairs of lateroventral setae. Metatarsi slender, slightly longer than maximum width of head, with tarsomere 1 much longer than tarsomere 2, but distinctly shorter than tarsomeres 2+3. Male protarsi markedly enlarged (tarsomeres 2 and 3 much wider than long and tarsomeres 1 to 4 with adhesive vestiture ventrally); mesotarsi moderately enlarged (tarsomere 1 narrow, distinctly longer than wide and with only a pair of adhesive scales apically; tarsomere 2 about 1.2 times as long as wide, with adhesive vestiture ventrally; tarsomere 3 approximately as long as wide, with adhesive vestiture ventrally; and tarsomere 4 small, deeply concave apically and without adhesive vestiture ventrally).
Aedeagus ( Figs 20-22 View Figures 16–22 ): Median lobe symmetrical, comparatively slender, markedly bent ventrad just behind basal bulb and with straight ventral margin. Sides rounded in middle portion and convergent in apical portion. Terminal lamella ( Fig. 20 View Figures 16–22 ) about 1.5 times as long as wide, triangular, narrowly rounded at apex, without apical capitulum. Apical orifice in dorsal position, prolonged to basal bulb. Internal sac without distinct sclerotic elements.
Fig. 56 View Figures 64–65 . This new species is known only from the type locality (Gutang Township) in the eastern Himalaya, the southeastern part of Xizang Autonomous region (Tibet), Medog County, China.
The specific epithet refers to Gutang in Xizang Autonomous Region, where the type specimen was collected.
This new species is isolated taxonomically from other known species of the genus and we include it in separate species group (the gutangensis group). Its members may be recognized by the following combination of characters: medial prosternal process distinctly projected posteriad, elytra with parascutellar strioles rudimentary and basal setigerous pores present, inner striae nearly effaced at apex, the umbilicate setal series without a gap at middle, metepisterna distinctly wider than long, slightly narrowed posteriad, metacoxae with a posteromedial setigerous pore and without additional setigerous or nonsetigerous foveae medially, and tarsi distinctly setose dorsally. The prosternum with the medial process distinctly projected posteriad is unique among all species of Chydaeus known to us. In adults of all other species, the medial prosternal process is either not or only slightly projected posteriad (as in Chydaeus hanmiensis described below).
The single known male of Chydaeus gutangensis is most similar to members of the irvinei group species (sensu Kataev and Schmidt 2002, 2006), which have metacoxae with an additional posteromedial setigerous pore, wide metepisterna and rudimentary parascutellar strioles, but is distinguished from them by the presence of the parascutellar setigerous pore on the elytra, dorsally setose tarsi, and greater body size (body length less than 8.0 mm in species of the irvinei group) among other features. Like members of some species of the irvinei group, the elytra of the holotype of Chydaeus gutangensis are fused along the suture.
The holotype male of Chydaeus gutangensis is similar also to the members of the kasaharai group in having wide metepisterna and additional posteromedial setigerous pores on the metacoxae, however it differs from them in having the body more elongate, the medial prosternal process distinctly projected posteriad, and the elytra with almost completely reduced parascutellar strioles, very fine striae that are effaced apically, and the umbilicate setal series more uniformly spaced, without a distinct gap near the middle.
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