Puertrechus daxueshanicus Belousov & Kabak

Belousov, Igor A. & Kabak, Ilya I., 2014, A new genus of trechine beetles, Puertrechus gen. n., with two new species and a new species of Dactylotrechus Belousov et Kabak, 2003 from Southern China (Coleoptera: Carabidae: Trechinae), Zootaxa 3856 (3), pp. 375-398 : 391-396

Puertrechus daxueshanicus Belousov & Kabak , sp. n.

( Figs. 11–14)

Type material: Holotype: 1(1)♂, “ CH, Yunnan Province, E sl. of Mt Daxueshan, W of Niutoushan Village, 24º07´15´´ N / 99º39´12´´ E, H= 3375 m, 3.06.2010, Belousov & Kabak leg.”( ZISP). Paratypes: 17(5)♂♂, 10(2)♀♀, collected together with holotype ( ZISP, ZSM, MPU, CAG, CAK, CBK, CDW, CMJ, CPM, CVZ); 6 (4)♂♂, 8 (2)♀♀, “ CH, Yunnan Province, Mt Daxueshan, W of Niutoushan Village, 24º06´53´´ N / 99º38´30´´ E, H= 3465 m, 7.06.2010, Belousov & Kabak leg.”( ZISP, ZSM, CBK); 1(1)♂, “ CH, Yunnan Province, SE sl. of Mt Daxueshan, W of Niutoushan Village, 24º06´42´´ N / 99º38´38´´ E, H= 3350 m, 6.06.2010, Belousov & Kabak leg.”( CBK). 10♂♂, 12♀♀ measured.

Description. Medium-sized species, body length 3.65–4.20 mm. Habitus ( Figs. 11–12) briefly ovate, strongly convex. Antennae and legs medium in length. Color blackish, with distinct amber-reddish tinge, head reddish piceous with blackish median spot on labrum; pronotum with paler reddish base and occasionally median longitudinal area; suture, margins and base of elytra also reddish; legs and antennae unicolorously pale amberreddish.

Head large, weakly narrower than pronotum. Eyes rather large, markedly produced beyond outline of head, clearly longer than tempora which are completely glabrous and evenly convex. Frontal furrows entire, subparallel in median part, deeply impressed behind middle, rather sharply curved and becoming very shallow posteriorly. Parietal impression distinct though shallow, frons convex. Supraorbital setiferous pores on lines subparallel to the body axis. Labrum clearly transverse, with anterior margin distinctly concave. Mandibles rather robust, more strongly curved apically, retinacle on the right mandible trilobed, each lobe being triangular shaped, with distal lobe longest and median lobe normally weakly shorter. Tooth on the left mandible weakly cleft apically or obliquely truncate. Clypeal suture straight. Last segment of antenna longest, the third and fourth segments marginally shorter and the second one shortest.

Pronotum slightly transverse, cordiform, with sides feebly constricted anteriad and strongly constricted posteriad. Digitiform processes short, directed mainly backward and only slightly outward. Basal margin of pronotum convex medially, and deeply emarginate laterally near hind angles. Anterior lateral setae located approximately at broadest point of pronotum, posterior one—markedly before level of basal margin and weakly displaced inward. Lateral border of pronotum more distinct anteriorly, becoming very fine in its posterior portion. Lateral groove very narrow in anterior part, effaced posteriorly. Discal foveae small and shallow but distinct. Basal foveae small and deep, completely smooth. Prebasal transverse impression rather shallow, base of pronotum smooth. Apical transverse impression mostly distinct, especially in lateral portions, located close to anterior margin. Apex of pronotum occasionally with some longitudinal wrinkles and punctures. Median line shallow, not reaching both the anterior and posterior margin.

Elytra ovate, with maximum width near mid-length, humeri distinct though strongly oblique, their apex broadly rounded or evenly truncate, re-entrant angle small but distinct. Lateral margins, including prehumeral area, evenly convex, slightly deflexed. Lateral groove moderate in width, gradually narrowing forwards and slightly dilated posteriorly. Disc of elytra moderately convex. Discal striae reduced: only striae 2–3 and fragments of stria 4 distinguishable in their middle portion. Stria 8 very shallow, distinguishable mostly near pores of umbilicate series. Parascutellar striole rather long, parascutellar setiferous pore present. Apical striole short and shallow, directed mostly outward and curved inward anteriorly. Anterior discal setiferous pore located at level slightly behind umbilicate pore 1, posterior one—between umbilicate pores 4 and 5, preapical pore—before level of umbilicate pore 7, clearly before anterior termination of apical recurrent striole, in apical cross (although striae 2 and 3 barely traceable here). Discal setiferous pore on site of stria 5 located in basal quarter of elytra distinctly behind anterior discal pore. Angulo-apical pore approximately in middle between exterior pore and elytral suture. First umbilicate pore varying in position, normally weakly shifted inward. Within groups of umbilicate series, pores 7 and 8 most spaced. Location of all pores of the umbilicate series as in Table 2 .

Microsculpture completely reduced, micropunctuation regular and distinct.

Two basal segments of the male protarsi dilated and dentate, the first segment being distinctly longer than wide and second approximately as long as wide.

Aedeagus ( Figs. 13–14 ) small, slender, strongly curved, with characteristic spoon-like and markedly swollen apical third. Ventral surface of the proximal half of the median lobe with rather deep and wide impression carinate laterally. Endophallus armature spatulate, moderately sclerotized, clearly shorter than the apex of the median lobe. Parameres slender, curved, with rather broad apices (often obliquely truncate ventrally), each bearing 4–5 apical setae; left one slightly longer, with a rather small ventral apophysis.

Sexual dimorphism. In addition to longer antennae, males differ from females in having longer legs (EL/TiL 1.81–1.95 (1.89) vs. 1.90–2.01 (1.94), at p<0.01, Mann & Whitney U -test).

Comparative notes. Though very similar to the type species of the genus, P. daxueshanicus sp. n. is readily distinguished in having: completely shining surface of body, without any trace of microsculpture; tempora more convex in median part; pronotum more transverse, with weaker sinuation before noticeably shorter hind angles more protruding backward; Lateral groove of both pronotum and elytra much narrower and less strongly reflexed; pronotal lateral border much finer; contour of elytra distinctly convex in prehumeral area; discal setiferous pore on site of stria 5 shifted more backward and located behind anterior fifth on elytral length, at level between umbilicate pores 3 and 4 (versus anterior sixth of elytral length at level between umbilicate pores 2 and 3 in P. mengsaensis sp. n.); preapical setiferous pore (third discal pore in stria 3), on the contrary, shifted anteriad and usually located clearly before level of umbilicate pore 7 while approximately at this level in P. mengsaensis sp. n. Apart from the above characters, P. daxueshanicus sp. n. is distinct in having slightly smaller size, shorter appendages, larger eyes, narrower elytra, and two anterior discal setiferous pores on elytra slightly shifted posteriad contrasting with the preapical pore weakly shifted anteriad as it was mentioned above (see Table 3). The aedeagus of P. daxueshanicus sp. n. is very similar to that of P. mengsaensis sp. n. ( Figs. 8–9 vs. 13–14) but the spoon-like apical portion of the median lobe markedly longer than the endophallus armature (not longer in its counterpart); the median lobe, in dorsal view, is less strongly curved to the left side; the proximal portion of the median lobe is much more strongly flattened dorso-ventrad, with its ventral surface carinate laterally; the dorsal margin of the median lobe clearly convex near the endophallus armature in lateral view.

P. mengsaensis P. daxueshanicus

Indices Range (average value) N Range (average value) N sex

Significance level p≤ 0.001

(D5/EL) x 100 13.84–19.87 (16.34) 20 18.36–26.44 (22.68) 22 both EW/PW 1.70–1.91 (1.80) 20 1.61–1.77 (1.69) 22 both PW/PL 1.10–1.22 (1.15) 20 1.16–1.28 (1.22) 22 both AL/EL 1.04–1.11 (1.07) 10 0.99–1.04 (1.02) 12 females YL/TL 1.43–1.77 (1.56) 20 1.60–1.96 (1.76) 22 both (D2/EL) x 100 30.27–47.02 (40.11) 20 40.44–50.95 (46.91) 22 both AL/EL 1.04–1.14 (1.09) 20 0.99–1.09 (1.04) 22 both EW/HW 1.95–2.17 (2.08) 20 1.92–2.08 (2.01) 22 both EL/TiL 1.85–1.92 (1.88) 10 1.90–2.01 (1.94) 12 females (U1/EL) x 100 8.33–13.61 (11.06) 20 7.59–12.46 (9.77) 22 both AL/EL 1.05–1.14 (1.10) 10 1.03–1.09 (1.06) 10 males PW/HW 1.11–1.22 (1.16) 20 1.16–1.22 (1.19) 22 both EL/PL 2.47–2.72 (2.59) 20 2.55–2.79 (2.66) 22 both EL/TiL 1.81–1.94 (1.87) 20 1.81–2.01 (1.92) 22 both

Significance level p≤ 0.01

EL/BH 1.94–2.25 (2.08) 20 2.04–2.32 (2.15) 22 both (DP/EL) x 100 75.31–83.77 (79.62) 20 69.62–82.03 (76.34) 22 both EL/EW 1.18–1.33 (1.26) 20 1.23–1.34 (1.29) 22 both (D1/EL) x 100 6.79–10.39 (8.59) 20 5.57–13.76 (10.12) 22 both (U8/EL) x 100 83.95–89.40 (87.08) 20 81.73–92.15 (85.54) 22 both

Significance level p≤ 0.05

L3/L2 1.24–1.44 (1.36) 10 1.19–1.37 (1.29) 10 males (PSa/PL) x 100 24.56–30.16 (27.44) 10 27.35–32.14 (29.02) 10 males YL/L3 0.96–1.14 (1.05) 20 1.00–1.21 (1.09) 22 both Body length, mm 3.75–4.23 (4.06) 20 3.65–4.20 (3.96) 22 both (U2/EL) x 100 11.42–17.09 (14.07) 20 10.76–15.25 (13.21) 22 both (U5/EL) x 100 55.56–62.58 (59.24) 20 55.76–61.64 (58.22) 22 both Distribution. Mount Daxueshan (Lincang Prefecture, Gengma Dai and Va Autonomous County), Yunnan Province, China. The range of this species seems to be confined to a small isolated mountain range located NNW of that of P. mengsaensis ( Fig. 15 , black circles).

Bionomics. Most specimens of this species were sifted from the wet litter on the banks of brooks within the zone of subalpine shrubs (consisting mostly of Rhododendron species) at elevations of 3350–3465 m while some specimens—from the moist litter accumulated near stones and trunks.

Figures

FIGURE 15. Distribution of Puertrechus species. 1 (black circle) — Puertrechus daxueshanicus gen. n., sp. n.; 2 (white circle) — Puertrechus mengsaensis gen. n., sp. n.

FIGURES 13 – 14. Male genitalia of Puertrechus daxueshanicus gen. n., sp. n.: a—lateral view with parameres, b—dorsal view, c—genitalic sac.

FIGURES 8 – 9. Male genitalia of Puertrechus mengsaensis gen. n., sp. n.: a—lateral view, b—dorsal view, c—parameres, d—genitalic sac.