Junnanotrechus koroleviellus Belousov & Kabak

Belousov, Igor A. & Kabak, Ilya I., 2014, A taxonomic review of the genus Junnanotrechus Uéno & Yin, 1993 (Coleoptera: Carabidae: Trechinae), with description of six new species, Zootaxa 3811 (4), pp. 401-437 : 422-433

Junnanotrechus koroleviellus Belousov & Kabak , sp. n.

( Figs. 21–22 )

Type material: Holotype: CHINA: 1(1)♂, ” CH, Yunnan Province, W of Yunxian Town, 24°28´29 N / 99°58´23´´ E, H= 2965 m, 17.06.2011, Belousov, Kabak, Korolev leg.( ZISP) { Fig. 35 : 12}. Paratypes: CHINA: 9(5)♂, 8♀ collected with the holotype ( MPU, CAK, CAG, CBK, CDW, CMJ, CPM, CVZ).

Description. Relatively small and gracile species with elongate and moderately convex body ( Figs. 21–22 ). Color of upper-side dirty brownish with paler elytra and anterior part of head; posterior part of head and often disk of pronotum darkest. Legs pale-brownish to dark testaceous, antennae strongly obscured beginning with the first antennomere, becoming increasingly paler toward apical antennomeres, in a way that 5–6 basal antennomeres clearly darker than others. Dorsal surface with rather distinct regular pubescence consisting of very short erect hairs. Lateral borders of both elytra and pronotum briefly and regularly ciliate.

Head rather small. Eyes small but convex, head across tempora approximately as wide as across eyes. Supraorbital carina not joining posterior edge of eye and partly surpassing anterior termination of eye carina being often angularly bent here. Tempora long, evenly convex, covered with sparse and long hairs. Frontal furrows regular, deep and continuous, arcuate, shallower in middle part, without distinct parietal impression. Supraorbital pores well-defined, anterior one moderately, posterior one slightly foveolate, located on imaginary lines clearly convergent posteriad. Two pairs of clypeal seta, of which inners shorter. Antennae, rather long, very thick, especially scapus; the second segment as long as segment three or even slightly longer. Labrum weakly concave, sexsetose. Mandibles slender, rather weakly curved; tooth on the right one clearly tridentate with well-defined premolar; distal denticle usually most protruding, occasionally rather obtuse, far distant from premolar; median denticle shortest, clearly shifted toward premolar. Labial tooth strongly protruding, cleft apically, longitudinally grooved ventrally. Mentum fused with submentum, though mental suture partially visible (especially so laterally). Usually 6 submental setae.

Pronotum weakly broader than in most congeners, markedly wider than long, with convex disk and sides very broadly rounded anteriorly, nearly straight posteriorly and occasionally briefly sinuate near anterior lateral seta. Hind angles of pronotum obtusangular, rounded apically. Basal margin slightly lobed: rectilinear or weakly convex medially, deeply incised laterally, with hind angles markedly shifted anteriad. Anterior margin salient, anterior angles rounded off. Lateral gutter narrow anteriorly, becoming increasingly wider posteriorly. Lateral border continuous and evenly developed. Prebasal transverse impression very close and parallel to basal margin of pronotum, deeply engraved. Base of pronotum behind prebasal impression densely and regularly to shallowly rugulose; basal foveae small, very shallow, their bottom surface smooth. Apical transverse impression rather shallow, more distinct laterally. Discal foveae small but distinct. Median line average, deepest toward base of pronotum.

Elytra oblong, with maximum width a little behind mid-length, strongly convex. Humeri obliquely rounded; both elytra conjointly rounded, nearly truncate; preapical sinuation shallow. Lateral border moderately deflexed, anteriorly joining basal border of elytra though slightly sinuate here. Only stria between scutellum and anterior part of elytral suture well-impressed. Parascutellar striole vestigial. Striae 1–3 very shallow, fragmentarily traceable only in their median parts, yet making possible exact localization of discal setigerous pores 1–2. Apical striole long, anteriorly nearly straight to slightly curved inward, disappearing at level weakly behind umbilicate pore 7. Parascutellar pore well-developed. Apart from preapical pore, three discal setigerous pores on each elytron, all discal setigerous pores clearly shifted posteriad. Two anterior setigerous pores located on site of stria 3, third pore weakly shifted outward and located mostly in stria 4, more seldom on interspace 4. Preapical pore in site of apical cross, approximately between striae 2 and 3, varying in longitudinal position at level slightly behind umbilicate pore 8. Apical triangle clearly elongate, inner side slightly convergent posteriad to suture. Umbilicate series wellaggregated in oblong direction, though umbilicate pores 7 and 8 a little more spaced while umbilicate pores 5 and 6 slightly approached. Umbilicate pores located at different distance from lateral margin, especially so concerning umbilicate pores 5 and 6, of which former is much farther removed from lateral border. Within humeral set, umbilicate pore 2 is closer to, umbilicate pore 4 farther from lateral border.

Microsculpture of dorsum rather distinct, though finely impressed, consisting of strongly transverse meshes and anastomosing lines. Surface of both pronotum and elytra strongly iridescent.

Front tibiae straight and rather thick, weakly grooved externally, their anterior surface glabrous, at most, with a few barely distinguishable hairs in apical quarter. Male protarsi with two basal segments strongly dilated and each provided with massive inner tooth; adhesive appendages elongate. Metatarsi rather long compared to other species.

Aedeagus ( Figs. 23–26 ) medium-sized, with rather long basal portion strongly step-like down-curved and apical part clearly attenuated ventrad in lateral view. In dorsal view, median lobe weakly S-shaped, subcylindrical for most its length except for apical quarter gradually attenuated toward apex ( Fig. 26 b). Apical disk rather large, oblique, without ventral projection, its dorsal protruding noticeably directed proximally. Sagittal aileron reduced, at most barely visible. Basal orifice not emarginate. Endophallus armature represented by a folded scaly area, located in more ventral position than in other members of the genus and rather poorly sclerotized with exception of its distal third. Parameres of medium length, moderately curved in median part, with thin, straight and parallel-sided distal portions, each bearing 3–5 (usually 4) apical setae and deprived of distinct ventral apophyses; left paramere clearly longer.

Sexual dimorphism. Sexual dimorphism is as described under the genus description.

Comparative notes. J. koroleviellus sp. n. is most closely related to the two southern congeners: J. oblongus sp. n. and J. elegantulus sp. n. described below. It shares with these species some important characters: the supraorbital carina not reaching the upper posterior edge of the eye, the pubescent body surface, the mentum and submentum fused and the margins of both the pronotum and elytra distinctly ciliated. As far as the structure of the male genitalia concerned, the new species is most similar to the neighboring J. oblongus sp. n., both species have well-developed scaly endophallus armature and large oblique apical disk. The close affinities of the above three species comply well with their geographic distribution ( Fig. 35 ). J. koroleviellus sp. n. is easily distinguished from both the aforesaid counterparts by the shape of the pronotum without distinct basal medial lobe ( Fig. 38 ) and rather flat eyes ( Figs. 21 – 22 ).

Distribution. The new species seems to be restricted to a small mountain massif (Xueshan Mount) located to the north of the Daxueshan Mt, W of Yunxian Town (Yun County, Lincang City Prefecture, Yunnan Province) ( Fig. 35 , white rhomb).

Bionomics. J. koroleviellus sp. n. was found only in the bed of a small mountain creek where it was sifted from thick broad-leaved and bamboo litter at an elevation of 2965 m a.s.l.

Derivatio nominis. We are extremely pleased to name this remarkable species after our friend and colleague, Dr. Alexander Korolev (St. Petersburg), who provided us with great assistance in preparing the present work.

Junnanotrechus oblongus Belousov & Kabak , sp. n. ( Figs. 27–30 )

Type material: CHINA: Holotype: 1(1)♂, “ CH, Yunnan Province, E sl. of Daxueshan, W of Niutoushan, 24°07´15´´ N / 99°39´12´´ E, H= 3375 m, 3.06.2010, Belousov & Kabak leg.( ZISP) { Fig. 35 : 13}. Paratypes: CHINA: 13(3)♂, 17(1)♀, collected with the holotype ( MPU, ZISP, CAK, CAG, CBK, CDW, CMJ, CPM, CVZ); 1♀, “ CH, Yunnan Province, E sl. of Daxueshan, W of Niutoushan, 24°05´30´´ N / 99°38´34´´ E, H= 3410 m, 6.06.2010, Belousov & Kabak leg.( CBK) { Fig. 35 : 15}; 3(2)♂, 3♀, “ CH, Yunnan Province, E sl. of Daxueshan, W of Niutoushan, 24°06´53´´ N / 99°38´30´´ E, H= 3465 m, 7.06.2010, Belousov & Kabak leg.( CBK) { Fig. 35 : 14}; 8(4)♂, 10(1)♀, “ CH, Yunnan Province, E sl. of Daxueshan, W of Niutoushan, 24°06´23´´ N / 99°38´27´´ E, H= 3460 m, 7.06.2010, Belousov & Kabak leg.( CBK, CDW, CAG).

Description. For the moment, the biggest species of the genus. Body shape strongly elongate-ovate and convex ( Figs. 27–28 ). Legs and antennae rather long and thick, especially femora of male robust. Color of upperside dirty brownish with a bit paler elytra and anterior part of head; posterior part of head clearly darkened, nearly blackish. Legs pale-brownish to dark testaceous, antennae clearly obscured beginning with second antennomere, very seldom unicolourously reddish. Dorsal surface with rather distinct regular pubescence consisting of very short erect hairs. Lateral borders of both elytra and pronotum briefly and regularly ciliate.

Head large. Eyes rather small but bigger than in other species, moderately convex. Head across tempora approximately as wide as across eyes. Supraorbital carina not long, either reaching approximately mid-level of eye or curved inwards at this level. Tempora long, evenly convex, covered with sparse and long hairs. Frontal furrows regular, deep and continuous, arcuate, shallower in middle part, without distinct parietal impression. Supraorbital pores well-defined, anterior one moderately, posterior one slightly foveolate, located on imaginary lines clearly convergent posteriad. Two pairs of clypeal seta, of which inners shorter. Labrum weakly concave, sexsetose. Mandibles slender, rather weakly curved; tooth on the right one clearly tridentate with well-defined premolar; distal denticle usually most protruding, occasionally rather obtuse, far distant from premolar; median denticle shortest, clearly shifted toward premolar. Labial tooth nearly triangular shaped, barely bifid apically. Usually 6 (more seldom 5—one median being wanted) submental setae, all corresponding pores well-developed. Mental suture completely reduced. Submentum often with transverse wrinkles.

Pronotum rather transverse anteriorly, convex and strongly constricted toward base. Its sides very broadly rounded anteriorly, nearly straight or barely sinuate before hind angles and often very shallowly sinuate near anterior lateral seta. Hind angles of pronotum small, obtusangular, rounded apically, markedly shifted anteriad. Basal margin slightly lobed: rectilinear or weakly convex medially, deeply incised laterally. Anterior margin salient, anterior angles rounded off. Lateral gutter rather regular, only slightly widened near hind angles. Lateral border continuous and evenly developed. Prebasal transverse impression very close and parallel to basal margin of pronotum, deeply engraved. Basal surface smooth; basal foveae small and very shallow. Apical transverse impression rather shallow, more distinct laterally. Discal foveae small but distinct. Median line average, becoming deeper toward base of pronotum.

Elytra oblong, with maximum width near mid-length, strongly convex. Humeri widely rounded; both elytra conjointly rounded, nearly truncate; preapical sinuation shallow. Lateral border moderately deflexed, strongly extended anteriad but not reaching basal carina on mesothoracic peduncle. All dorsal striae including stria 8 reduced. First discal stria distinct only on basal slope of elytra between scutellum and parascutellar setigerous pore, being rather straight for most length, more sharply engraved and barely sinuate just in front of the latter presumably due to vestigial parascutellar striole located there. Anterior part of the latter sharply carinate or even with a distinct tubercle. Apical striole long, straight, occasionally weakly curved outward, disappearing at level before umbilicate pore 8. Parascutellar pore well-developed; parascutellar striole rather distinct, carinate interiorly. Apart from preapical pore, three discal setigerous pores on each elytron. Two anterior pores located on site of stria 3, third pore a bit shifted outward and located normally on interspace 4, much more seldom in stria 4 or even in stria 3. Both second and third setigerous pores rather strongly shifted posteriad compared to other species. Preapical pore approximately between sites of striae 2 and 3, at level near umbilicate pore 8. Apical triangle elongate. Umbilicate series well-aggregated in oblong direction, though umbilicate pores 7 and 8 a little more spaced while umbilicate pores 5 and 6 slightly approached. Umbilicate pores located at different distance from lateral margin, especially so concerning umbilicate pores 5 and 6, of which former is much farther removed from lateral border. Within humeral set, umbilicate pore 2 is closer to, umbilicate pore 4 farther from lateral border.

Microsculpture extremely shallow but distinguishable on head, more distinct but very finely impressed on pronotum and elytra, consisting here of strongly transverse meshes and anastomosing lines. Surface of both pronotum and elytra strongly iridescent.

Front tibiae straight and rather thick, weakly grooved externally, their anterior surface with a few brief hairs in apical quarter, some specimens with a few longer hairs just near apex. Male protarsi with two basal segments strongly dilated and each provided with massive inner tooth, even segment 1 clearly wider than long; adhesive appendages elongate.

Aedeagus ( Fig. 29 – 30 ) rather large, with basal part of median lobe proportionally big and curved ventrally approximately in proximal third, apex button-like and set largely perpendicular to distal part of aedeagus, protruding both ventrally and dorsally in lateral view. Maximum width of aedeagus slightly before its mid-length In dorsal view, median lobe slightly arcuate and distinctly attenuating toward apex, which more or less strongly truncate. Sagittal aileron small, barely protruding; basal orifice not emarginate. Endophallus armature representing a large moderately sclerotized scaly area filling nearly completely straight distal portion of median lobe, widely rounded proximally and clearly folded in median part in dorsal view. Parameres short, strongly curved in median part, with very thin, straight and parallel-sided distal portions, each bearing 4 very short apical setae (often overlapped in lateral view) and deprived of distinct ventral apophyses; left paramere clearly longer.

Sexual dimorphism. As described under the genus description.

Variation. Interestingly, some specimens of this species are distinct in having one additional discal seta on either the left or right elytron. In this case, it becomes obvious that additional seta is located in stria 3, while exterior setigerous pore is attached to stria 4.

Comparative notes. J. oblongus sp. n. seems to be most closely related to J. koroleviellus sp. n. described above. These species share the following characters: the elongate habitus, the brief and sparse but distinct pubescence of the body surface, the lateral border of the pronotum complete between the anterior and posterior lateral setae, the similar shape of the pronotum, the strong curvature of the median lobe in the male genitalia, the apical disc of the median lobe more markedly developed and some others. J. oblongus sp. n. differs readily from J. koroleviellus sp. n. in having the much larger body size (see Table 3), larger and more convex eyes, the pronotum with the hind angles more strongly shifted anteriad and with its base more pedunculate ( Fig. 39 vs. Fig. 38 ), the pronotal base less densely rugulose and some other external characters of minor importance. The aedeagus of J. oblongus sp. n. is much bigger, with apical disk nearly perpendicular to the apical portion of the median lobe and provided with a distinct ventral protruding ( Figs. 29 – 30 vs. Figs. 23 – 26 ); the parameres proportionally smaller; the endophallus armature more developed.

Indices Range (average), N Range (average), N J. elegantulus and J. koroleviellus

Length mm 3.14–3.68 (3.39), 20 3.00–3.46 (3.15), 18 PW/HW 1.03–1.14 (1.10), 20 1.28–1.34 (1.30), 18 AL/EL 1.05–1.18 (1.11), 20 0.93–1.05 (1.00), 18 L3/W3 1.87–2.40 (2.12), 20 1.56–1.92 (1.74), 18 L3/L2 1.07–1.23 (1.15), 20 0.93–1.07 (1.01), 18 PW/PL 0.98–1.09 (1.02), 20 1.10–1.22 (1.15), 18 PA/PB 1.05–1.26 (1.17), 20 1.03–1.16 (1.09), 18 EW/HW 1.78–1.97 (1.88), 20 1.87–2.12 (1.96), 18 EW/PW 1.62–1.86 (1.72), 20 1.42–1.62 (1.51), 18 (D3/EL) x 100 76.9–87.6 (82.3), 20 86.3–95.1 (90.6), 18 (D4/EL) x 100 52.3–65.7 (57.8), 20 57.5–67.4 (63.1), 18 (U7/EL) x 100 80.0–86.3 (82.9), 20 77.3–83.1 (80.5), 18 EL/TiL 1.84–2.14 (1.99), 20 2.02–2.23 (2.12), 18

......continued on the next page Indices Range (average), N Range (average), N J. elegantulus and J. oblongus

On the other hand, J. oblongus sp. n. is similar to J. elegantulus sp. n. described below. Their differences are considered later.

Distribution. J. oblongus sp. n. inhabits the area situated between the geographic species range of J. elegantulus sp. n. and other known members of the genus Junnanotrechus . For the time being, the species is known from the Daxueshan Mount, located W of Niutoushan Village (Gengma Dai and Va Autonomous County of the Lincang Prefecture), Yunnan Province. ( Fig. 35 , black circle).

Bionomics. J. oblongus sp. n. seems to be relatively common (for the genus) in the region inhabiting a range of biotopes which were not mandatory confined to valleys of mountain creeks. The species was found by sifting the rich broad-leaved and bamboo litter at elevations between 3375 and 3465 m.

Junnanotrechus elegantulus Belousov & Kabak , sp. n. ( Figs. 31–32 )

Type material: Holotype: CHINA: 1(1)♂, “ CH, Yunnan Province, Mt. Daxueshan E Mengsa Town, 23°42´26´´ N / 99°47´26´´ E, H= 3045 m, 30.05.2010, Belousov & Kabak leg.( ZISP) { Fig. 35 : 16}. Paratypes: CHINA: 17(3)♂, 20♀, collected with the holotype ( MPU, ZISP, CAK, CAG, CBK, CDW, CMJ, CPM, CVZ).

Description. Small-sized species with ovate and convex body strongly constricted at pronotal base; legs and antennae rather long and thin ( Figs. 31–32 ). Color of upper-side dark dirty brownish, anterior part of head in front of clypeal suture paler; appendages a little paler, brownish; femora slightly, antennae clearly darkened beginning with apical half of antennomere 3–4. Dorsal surface with rather distinct regular pubescence consisting of very short erect hairs more visible on apical slope of elytra. Lateral borders of both elytra and pronotum extraordinarily briefly ciliate.

Head very large, head across tempora markedly wider than across eyes. The latter very small, moderately convex and regularly ovate. Supraorbital carina not long, reaching approximately mid-level of eye, disappearing far from upper edge of eye. Tempora long, very strongly and evenly convex, covered with sparse and long hairs. Frontal furrows regular, deep and continuous, arcuate, shallower in middle part, without distinct parietal impression. Supraorbital pores well-defined, anterior one moderately, posterior one slightly foveolate, located on imaginary lines clearly convergent posteriad. Two pairs of clypeal seta, of which inners shorter. Labrum weakly concave, sexsetose. Mandibles slender, rather weakly curved; tooth on the right one clearly tridentate with welldefined premolar; distal denticle usually most protruding, occasionally rather obtuse, unusually far spaced from premolar; median denticle as a low carina more distinctly protruding toward premolar and occasionally ending with a small denticle there. Labial tooth more or less distinctly bifid at apex. 6 submental setae, of which median pair is shortest, their punctures barely visible, therefore in non-dissecting specimens may be easily overlooked. Two long median setae on glossum and 3 much shorter lateral setae on each side of glossum. Mentum completely fused with submentum, mental suture totally missing.

Black circle— Junnanotrechus oblongus Belousov & Kabak , sp. n.

Black rhomb— Junnanotrechus exophtalmus Deuve, 1998 and Junnanotrechus baehri Deuve, 2011 Black square— Junnanotrechus wrasei Belousov & Kabak , sp. n.

Black triangle— Junnanotrechus schuelkei Belousov & Kabak , sp. n. White circle— Junnanotrechus elegantulus Belousov & Kabak , sp. n. White rhomb— Junnanotrechus koroleviellus Belousov & Kabak , sp. n. White square— Junnanotrechus microps Uéno & Yin, 1993

White triangle— Junnanotrechus triporus Belousov & Kabak , sp. n.

Pronotum peculiarly shaped: hind angles with posterior lateral setae strongly shifted forwards, rendering pronotum to be pedunculate. Pronotum narrow, rather convex, though its disk clearly depressed in anterior third along median line. Sides evenly rounded anteriorly, gradually and very weakly sinuate before hind angles. Latter rounded though salient. Lateral border extremely fine, between anterior and posterior lateral setae next to reduced, though discernible, and completely reduced behind posterior lateral seta. Lateral impression irregular, shallow, developed mostly near anterior lateral seta. Anterior margin salient, clearly longer than basal margin (PA to PB ratio being maximum among members of genus), anterior angles completely rounded off. Prebasal transverse impression parallel to basal margin of pronotum, deeply engraved, especially so as compared to strongly convex disk. Basal surface smooth except for posteriormost portion which is finely longitudinally rugulose. Basal foveae reduced to small impressions similar to those of prebasal transverse impression. Apical transverse impression welldefined, more regular and finely delimited laterally, very deep but not distinctly delimited medially; all apical surface of pronotum finely rugulose and punctured. Median line rather deep, especially so near apical transverse impression, not reaching anterior margin of pronotum, becoming deeper near prebasal transverse impression and shallow at base of pronotum.

Elytra ovate, narrow, with maximum width near mid-length, strongly convex though occasionally weakly depressed along suture. Humeri widely rounded; both elytra conjointly rounded, nearly truncate; preapical sinuation shallow. Lateral border moderately deflexed, strongly extended anteriad but not reaching mesothoracic peduncle. Discal striae reduced: at most, fragments of striae 1–2 distinguishable. First discal stria distinct on basal slope of elytra between scutellum and parascutellar setigerous pore, evenly impressed and gradually sinuate.

Apical striole long, straight, occasionally weakly curved outward, disappearing at level between umbilicate pores 7 and 8. Parascutellar pore and tubercle well-developed; parascutellar striole rather distinct, carinate interiorly. Apart from preapical pore, three discal setigerous pores on each elytron. Two anterior setigerous pores located on site of stria 3, third pore weakly shifted outward and located either in anastomosis of striae 3 and 4 or in stria 4. Preapical pore in apical cross, i.e. between striae 2 and 3, varying in longitudinal position from level of umbilicate pore 6 to umbilicate pore 7 (in most anterior position compared to other congeners). Therefore, apical triangle from long to extremely long. Umbilicate series well-aggregated in oblong direction: divided into three usual groups but its pores located at different distance from lateral margin: only umbilicate pore 2 markedly approaching lateral border; all umbilicate pores within groups subequidistant.

Microsculpture completely obliterate on median part of frons, fine but discernible on occiput and tempora, extremely shallow and consisting of transverse and partly anastomosing lines on pronotum and on elytra. Surface of both pronotum and elytra iridescent.

Lateral sides of sternum glabrous, smooth and shining, ventral surface of prosternum extremely scarcely pubescent and micropunctured. Anal sternite very scarcely and briefly pubescent in posterior half. All other ventral sternites with very scares and short hairs, arranged mostly in one transverse row, this pubescence becoming usually more distinct on posterior ventrites.

Front tibiae straight and rather slender, strongly grooved externally, their anterior surface with rather long though very sparse hairs in apical third. Male protarsi with two basal segments strongly dilated and each provided with massive inner tooth, even segment 1 clearly wider than long; adhesive appendages elongate.

Aedeagus ( Fig. 33 ) medium-sized, median lobe obtusangularly curved at base, slightly depressed dorsoventrally toward apical third; its basal part relatively long, distal portion with nearly rectilinear ventral side; apex curved upward, without ventral protruding. In lateral view, maximum width of median lobe in proximal half. Sagittal aileron medium-sized, weakly redoubled apically; basal orifice small and not emarginate. In dorsal view, median lobe with maximum width in distal third and clear constriction at level of basal bent, apex rather small but well defined. Endophallus armature represented by a rather distinctly sclerotized scaly area completing nearly all distal portion of aedeagus tube; this area divided into three main pieces: proximal piece, distal one and dorsal-distal piece. Parameres feebly curved, with narrow and strongly attenuating distal portions; each bearing 4 apical setae and deprived of distinct ventral apophyses; left paramere much longer.

Comparative notes. J. elegantulus sp. n. seems to be a rather isolated species within the genus. From all hitherto known congeners, it differs readily by a quite peculiar shape of the pronotum with its basal portion very strongly pedunculate and hind angles strongly shifted forwards ( Fig. 41 ) as well as by the lateral border of the pronotum partially reduced between the anterior and posterior lateral pores. Additionally, J. elegantulus sp. n. is easily distinguishable from all other species of Junnanotrechus in having the rather unusual habitus with very large head (its width across tempora clearly wider than across eyes), briefly ovate elytra, very small eyes and slender antennae and legs.

Among all Junnanotrechus species, J. elegantulus sp. n. is most similar to J. oblongus sp. n. sharing with this species the following characters: the well-developed pubescence of the dorsum, the hind angles of the pronotum more strongly shifted anteriad as compared with other congeners, the third discal setigerous pore less clearly shifted outward and normally located on interspace 4. Apart from the unique characters listed in the previous paragraph, J. elegantulus sp. n. differs from J. oblongus sp. n. by the smaller body size and much smaller aedeagus with the apex only weakly curved upward ( Fig. 33 vs. Figs. 29 – 30 ).

To summarize, as far as the morphological characters concerned, J. oblongus sp. n. occupies an intermediate position between J. elegantulus sp. n. and J. koroleviellus sp. n. that complies well with their geographic distribution.

Sexual dimorphism. Apart from the common sexual differences shared by this species with other congeners, J. elegantulus sp. n. possesses a rather pronounced sexual dimorphism in size: females are, on average, clearly bigger than males (the difference is significant at a p<0.001 level).

Distribution. The southernmost species of the genus, for the moment, known only from the Daxueshan Mount (another mountain massif with the same name as in the case of the previous species, this mountain is located E of Mengsa Village on the boundary between Gengma Dai and Va Autonomous County and Shuangjiang Lahu, Va, Bulang and Dai Autonomous County of the Lincang City Prefecture), Yunnan Province ( Fig. 35 , white circle).

Bionomics. J. elegantulus sp. n. was found only in one site, along the riparian zone of a small creek by sifting from litter debris at an elevation of 3045 m ( Fig. 34 ).

Figures

FIGURE 33. Male genitalia of Junnanotrechus elegantulus sp. n.: a—lateral view, b—dorsal view, c—genital segment.

FIGURE 34. Typical biotope of Junnanotrechus elegantulus sp. n.

FIGURE 35. Distribution of Junnanotrechus species.

FIGURES 21 – 22. Junnanotrechus koroleviellus sp. n., habitus: 21 — male paratype; 22 — female paratype.

FIGURES 23 – 26. Male genitalia of Junnanotrechus koroleviellus sp. n.: a—lateral view, b—dorsal view, c—parameres, d—genital segment.

FIGURES 36 – 41. Junnanotrechus spp, pronotum: 36 — J. baehri Deuve; 37 — J. triporus sp. n.; 38 — J. koroleviellus sp. n.; 39 — J. oblongus sp. n.; 40 — J. schuelkei sp. n.; 41 — J. elegantulus sp. n.

FIGURES 27 – 28. Junnanotrechus oblongus sp. n., habitus: 27 — male paratype; 28 — female paratype.

FIGURES 29 – 30. Male genitalia of Junnanotrechus oblongus sp. n.: a—lateral view, b—dorsal view, c—genital segment.

FIGURES 31 – 32. Junnanotrechus elegantulus sp. n., habitus: 31 — male paratype; 32 — female paratype.