Puertrechus mengsaensis 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 : 386-391

Puertrechus mengsaensis Belousov & Kabak , sp. n.

( Figs. 6–9)

Type material: Holotype: 1(1)♂, “ CH, Yunnan Province, Mt. E Mengsa Town, 23º42´26´´ N / 99º47´26´´ E, H= 3045 m, 30.05.2010, Belousov & Kabak leg.”( ZISP). Paratypes: 117(5)♂♂, 76(3)♀♀, collected together with holotype ( ZISP, ZSM, MPU, CAG, CAK, CBK, CDW, CMJ, CPM, CVZ). 10♂♂, 10♀♀ measured.

Description. Medium-sized species, body length 3.75–4.25 mm. For all morphometric characters of this and the next species see Table 2 . Habitus ( Figs. 6–7) briefly ovate, strongly convex, with relatively strong constriction at pronotal base. Antennae and legs medium in length. Colour amber-reddish with darker, nearly blackish lateral sides of pronotum (these spots often merged medially) and disc of elytra; the suture, margins and base of elytra usually reddish; head mostly reddish, with blackish narrow median spot on labrum and occasionally vague darkening in posterior part; legs and antennae usually unicolorously reddish, seldom barely obscured in median and distal parts.

Head large, clearly narrower than pronotum. Eyes rather large, strongly produced beyond outline of head, clearly longer than tempora which are completely glabrous and evenly convex. Frontal furrows entire, subparallel in median part, becoming much deeper near level of clypeal suture and approximately at level of anterior supraorbital setiferous pores, rather sharply curved and becoming very shallow posteriorly. Parietal impression shallow, frons convex. Supraorbital setiferous pores on lines subparallel to the body axis. Labrum clearly transverse, with anterior margin shallowly concave. Mandibles rather robust, weakly and gradually curved, tooth on the right mandible trilobed, each lobe being triangular-shaped, with distal lobe longest and median lobe shortest. Tooth on left mandible weakly cleft apically. Clypeal suture straight. Ultimate segment of antenna longest, third and fourth antennomeres weakly shorter, and second one being shortest.

Pronotum rather small, cordiform, with sides briefly rounded in anterior third and strongly constricted and sinuate in posterior half. Digitiform processes rather short, directed back- and outward, basal margin of pronotum weakly convex, except for its most lateral portions which are deeply emarginate. Anterior lateral setae located at broadest point of pronotum, posterior one—markedly shifted anteriad from basal margin. Lateral border of pronotum rather thick in anterior half, becoming very fine in posterior half. Lateral groove of pronotum distinct in anterior part, more or less reduced 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 barely distinguishable except for lateral parts. Apex of pronotum finely longitudinally rugulose. Median line rather shallow, not reaching anterior margin, slightly deepening toward preapical transverse impression but not projecting beyond it.

Elytra briefly ovate, their maximum width near mid-length, with distinct though strongly oblique humeri and broadly rounded apex, re-entrant angle distinct. Disc of elytra moderately and evenly convex. Lateral groove wide for most of its length, gradually narrowing only before humeri, slightly deflexed throughout. Discal striae reduced: only fragments of three inner striae visible. Eighth stria very shallow, distinguishable near pores of umbilicate series. Parascutellar striole rather long, parascutellar seta present. Apical striole short and shallow, directed mostly outward and curved inward anteriorly. Anterior discal pore located before level of umbilicate pore 1, posterior one—at level between umbilicate pores 4 and 5, preapical pore—at level near umbilicate pore 7, clearly before anterior termination of apical recurrent striole; with traces of striae 2 and 3 anastomosing here. Discal setiferous pore on site of stria 5 located in basal sixth of elytra slightly behind anterior discal pore. Angulo-apical pore approximately in middle between exterior pore and elytral suture. First umbilicate pore varying in position, more or less strongly shifted inward (distance between umbilicate pores 1 and 2, on average, 3% vs. 4.7% between pores 2 and 3). Location of all pores of umbilicate series as in table 2.

Microsculpture shallow though distinct, effaced only on some parts of head, consisting of more or less transverse meshes on elytra and pronotum and less transverse, nearly isodiametric meshes on head; upper-side evenly and strongly micropunctured.

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

Aedeagus ( Figs. 8–9 ) of very characteristic shape, median lobe slender in basal part, weakly dilated in apical third. In lateral view, the endophallus armature is approximately as long as the spoon-like apex. Latter nearly perpendicularly truncate in lateral view while curved to left side and broadly rounded in dorsal view. Ventral flattening of the median lobe rather weak. Parameres thick, arched; with rather broadly rounded apices, each bearing 4-5 apical setae; ventral processus on the left paramere well-developed.

Sexual dimorphism. Sexual dimorphism is very slightly expressed. Apart from longer antennae, males are distinct in having narrower elytra (EL/EW, on average, 1.27 vs. 1.24 in females, the difference significant at p<0.05, Mann & Whitney U -test).

Distribution. P. mengsaensis sp.n. was found only in one locality on Daxueshan Mount located East of Mengsa Town, (Lincang Prefecture) on the boundary between Gengma Dai and Va Autonomous County and Shuangjiang Lahu, Va, Bulang and Dai Autonomous County, Yunnan Province, China ( Fig. 15 , white circle). Bionomics. The species was sifted from flood debris on banks of a small mountain brook in a broad-leaved forest at an elevation of 3045 m ( Fig. 10 ).

Figures

FIGURE 10. Typical biotope of Puertrechus mengsaensis gen. n., sp. n.

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

Tables

TABLE 2. Morphometric characters of Puertrechus mengsaensis gen. n., sp. n. and P. daxueshanicus gen. n., sp. n.

Indices	P. mengsaensis Range (average value)	P. daxueshanicus Range (average value)
Body length, mm	3.75–4.25 (4.06)	3.65–4.20 (3.96)
PW/HW	1.11–1.22 (1.16)	1.16–1.22 (1.19)
YL/TL	1.43–1.77 (1.56)	1.60–1.96 (1.76)
YL/L3	0.96–1.14 (1.05)	1.00–1.21 (1.09)
AL/EL	1.04–1.14 (1.09)	0.99–1.09 (1.04)
L3/L2	1.24–1.52 (1.36)	1.17–1.45 (1.32)
L3/W3	2.31–2.69 (2.48)	2.25–2.80 (2.49)
PW/PL	1.10–1.22 (1.15)	1.16–1.28 (1.22)
PW/PB	1.45–1.71 (1.55)	1.51–1.64 (1.57)
PA/PB	1.08–1.26 (1.18)	1.12–1.23 (1.18)
EL/EW	1.18–1.33 (1.26)	1.23–1.34 (1.29)
EL/PL	2.47–2.72 (2.59)	2.55–2.79 (2.66)
EW/HW	1.95–2.17 (2.08)	1.92–2.08 (2.01)
EW/PW	1.70–1.91 (1.80)	1.61–1.77 (1.69)
EL/BH	1.94–2.25 (2.08)	2.04–2.32 (2.15)
EL/TiL	1.81–1.94 (1.87)	1.81–2.01 (1.92)
TiL/TaL	1.37–1.57 (1.44)	1.38–1.55 (1.43)
(PSa/PL) x 100	24.6–33.6 (28.6)	25.7–32.1 (29.4)
(D1/EL) x 100	6.8–10.4 (8.6)	5.6–13.8 (10.1)
(D2/EL) x 100	30.3–47.0 (40.1)	40.4–50.95 (46.9)
(D5/EL) x 100	13.8–19.9 (16.3)	18.3–26.4 (22.7)
(DP/EL) x 100	75.3–83.8 (79.6)	69.6–82.0 (76.3)
(U1/EL) x 100	8.33–13.6 (11.1)	7.59–12.5 (9.77)
(U2/EL) x 100	11.4–17.1 (14.1)	10.8–15.3 (13.2)
(U3/EL) x 100	16.7–21.2 (18.8)	14.4–20.6 (18.2)
(U4/EL) x 100	22.5–27.8 (24.9)	20.6–27.8 (24.4)
(U5/EL) x 100	55.6–62.6 (59.2)	55.8–61.6 (58.2)
(U6/EL) x 100	60.5–68.4 (65.3)	62.3–77.0 (64.8)
(U7/EL) x 100	75.9–83.4 (79.0)	73.8–84.2 (78.5)
(U8/EL) x 100	84.0–89.4 (87.1)	81.7–92.2 (85.5)