Psychristus (Psychristus) brunneus, Jaeger & H, 2009

Jaeger, B. & H, Ban, 2009, Two new species of Psychristus subgenus Psychristus ANDREWES 1930 from Southeast Asia, India and Pakistan, with additions to the Psychristus discretus group (Col., Carabidae), Linzer biologische Beiträge 41 (2), pp. 1635-1657 : 1639-1642

publication ID	https://doi.org/ 10.5281/zenodo.5279282
persistent identifier	https://treatment.plazi.org/id/039F194A-C345-EC28-FF06-1B8FFC77FD3C
treatment provided by	Carolina
scientific name	Psychristus (Psychristus) brunneus
status	sp. nov.

Treatment

Psychristus (Psychristus) brunneus View in CoL nov.sp. ( Figs 4-6 View Figs 4-6 , 13-17 View Figs 13-17 , 23 View Figs , 26 View Figs 26-27 , 29 View Figs 28-32 )

T y p e m a t e r i a l:H o l o t y p e 3 ( NHMB) labelled " LAOS-C; KHAM Mouan pr.; / Ban Khoun Ngeun; ~ 200 m; / 18°07’N 104°29’E / Pacholátko leg.; 24.-29.iv. 2001 " and " HOLOTYPE 3 / Psychristus (s.str.) / brunneus spec. nov. / des. B. Jaeger 2009" GoogleMaps .

P a r a t y p e s (1233, 29♀♀): Laos: 233, 6♀♀ ( NHMB, cJAE) with same label data as holotype. 3♀♀ ( NHMB) with same label data, except date " 19.-31.v. 2001 ". 13 ( NHMB) labelled " LAOS, 1-18.v.2001, / Bolikhamzai prov., / 18°21’N 105°08’E / Ban Nape (8 km NE) / ~ 600 m, V. Kubáň leg ". 1 3 (cWRA) labelled "N LAOS / 10 km N Luang Prabang / Mekong riv. (240 km N / Vientiane) XII 1992 ", "hilly country /sparse settled / primary vegetation / Insomsay Somsy leg." and "Coll. WRASE / BERLIN" (green label). 13, 3♀♀ ( MNHUB) labelled " NORD LAOS xii. 1992 / 10 km N Luang-Prabang / Mekhong river , 240 km N / Vientiane, hills ca. 250m / poor settlem., prim veget / lux, leg. Insomsay Somsy " GoogleMaps ; 13 ( MNHUB) with same label data, except date " xi. 1992 " ; 2♀♀ ( MNHUB) with same label data, except date " ii. 1993 ", and 1 3, 6 ♀♀ ( MNHUB, cJAE) with same label data, except date " iii. 1993 " .

Thailand: 2♀♀ (NHMB, cJAE) labelled " Thailand 91 / "Thanon Thong Chai" / D. Král & V. Kubáň" and "THAI, 9.-14.V. 1991 / CHIANG DAO 350 m / 19°22’N 98°57’E / Vit Kubáň leg.".

13 (SMNS) labelled "NW THAILAND Soppong / 700 m, 23.IV.2004 /leg. W. SCHAWALLER". India: 233, 6♀♀ (NHMB, cJAE) labelled " INDIA: Orissa state / Similipal N.P., Lulung / 21°56’N 86°32’E / 25.v.-13.vi.1998 / Karel & Simon Majer leg.". 13 (cWRA) labelled "N-INDIA / (Uttar Pradesh) / Rishikesh / 8.VII. 1989 A. Riedel".

Indonesia: 1 3 (cWRA) labelled " INDONESIA Tanimbar Isles / Yamdena Isle /Lorulun vill. env. / 20 km NE Saumlaki 150 m / 25.XI.-24.XII. 2006 St. Jakl" and "Coll. WRASE / BERLIN" (green label).

Pakistan: 1♀ (ZISP) labelled " PAKISTAN / Islamabad / 10.VII.2003 / S. Ovchinnikov leg.", " Psychristus / (? subg. n.?) / sp. n." [red] and "Zoolog. Institute / RAN / ST. Petersburg".

All paratypes labelled additionally " PARATYPE 3 or ♀ (as appropriate)/ Psychristus (s.str.) / brunneus spec. nov. /des. B. Jaeger 2009"

D e s c r i p t i o n: General appearance as figured ( Fig. 4 View Figs 4-6 ). Body length 3.5-4.3 mm (holotype 3.9 mm); width 1.4-1.8 mm.

Ground colour of dorsal and ventral surface paler to darker yellowish to pale reddish brown. Head usually, except paler clypeus, labrum and mandibles, and often elytra, except paler sutural interval, darker brown. Apical half or third, often also the base of lateral margin of mandibles blackened. Legs, antennae and palpi yellowish brown.

Head ( Figs 4-6 View Figs 4-6 ) including eyes, comparatively broad, 0.82-0.92 times as wide as pronotum, with eyes large and hemispherically prominent (head 1.55-1.65 times as wide as head between eyes). Apical margin of labrum rectilinear or weakly emarginated with a small rounded projection medially. Mentum with epilobes ( Fig. 29 View Figs 28-32 ) only very weakly projecting forward, without distinctly acuminate apices. Mental tooth large and sharp, as long as or slightly longer than epilobes. Ligula triangularly acuminate at apex, usual pair of setae inserted distinctly posterior to apical margin. Mandibles large and markedly prolonged and curved, not truncate at apices. Antennae 1.74-1.94 times as long as pronotum and 0.64-0.70 times as long as elytra, with antennomere 1 and 2 glabrous, except for usual setae, 3 moderately pubescent and 4-11 distinctly pubescent. Microsculpture obsolete, except for isodiametric meshes on labrum.

Pronotum ( Figs 4-6 View Figs 4-6 ) somewhat cordate, 1.23-1.34 times as wide as long and 1.09-1.22 times as wide as head, widest just behind anterior third, lateral seta inserted somewhat anterior to this. Surface somewhat convex on disc, weakly bent downward to anterior angles and somewhat depressed at basal area. Anterior margin arcuate, faintly bordered at sides, angles not or weakly projecting forward and relatively broadly rounded at tips. Sides convex in anterior two-thirds and at posterior third rectilinear and weakly constricted, or almost parallel, or slightly sinuated in front of pronotal base. Posterior angles obtuse, but comparatively sharp, usually with a small denticle at tip. Base about as wide as or slightly wider than apical margin between anterior angles and 0.79-0.86 times as wide as maximum pronotal width, arcuate medially and somewhat oblique to posterior angles. Lateral furrows distinct, confluent with lateral basal impressions at basal quarter. Basal foveae varies in shape, somewhat roundly or linearly impressed, sometimes separated by a shallow convexity from lateral margin, sometimes flattened to basal and lateral margin, the latter somewhat reflexed. Base in, around and between basal foveae moderately punctured; punctation often somewhat extended laterally by a few punctures at sides and in lateral furrows. Apical area before anterior impressions also with few scattered punctures. Median line moderately impressed, reaching basal margin and disappearing just in front of anterior margin, faintly to moderately punctate in basal quarter and finely punctate or impunctate in medial and apical part. Anterior transverse impression moderate. Microsculpture almost obsolete, rarely with few mesh rudiments in basal foveae.

Macropterous. Elytra ( Fig. 4 View Figs 4-6 ) 1.51-1.64 times as long as wide, 2.67-2.88 times as long and 1.32-1.45 times as wide as pronotum. Surface weakly convex. Sides slightly diverging posteriorly, widest at about middle or just behind this. Subapical sinuation moderate. Humeri distinctly developed, with a small, usually slightly projecting humeral tooth. Basal bead arcuately turning into humerus and forming a distinct angle with lateral margin. Scutellar pore puncture present, scutellar striae lacking. Elytral striae moderately impressed and impunctate, intervals flat to very lightly convex, intervals 2 and 3 comparatively flat and wide at apex, interval 2 sometimes somewhat dilated. Interval 3 in posterior half without a setiferous pore at stria 2. Series umbelicata 6 (5+1) - 8 (4-2+2). Microsculpture almost obsolete except isodiametric meshes on scutellum, and on base of elytra anterior to basal margin.

Ventral surface without pubescence and almost impunctate, rarely prosternum and proepisterna with few punctures (at proepisterna very shallow). Prosternal process with two longer setae. Metepisterna distinctly narrowed posteriad, at inner margin about 1.7 times as long as basal margin. Abdominal sternites 3-5 with usual pair of setae, sternite 6 at apical margin with two setae at each side in males and females.

Legs: Pro- and mesotarsi somewhat wider than in other species of P. discretus group, but in this respect without differences between males and females. Protarsomeres 2-3 of males ventrally each with one inner pair of longer modified setae (long and narrow, but somewhat flattened/widened), which probably have adhesive function, but differ distinctly from typical adhesive hairs known from other species of the genus. Protarsomeres of females and mesotarsomeres in both sexes without adhesive hairs ventrally, but in protarsomere 4 the apical setae sometimes somewhat flattened in both sexes. Protarsomeres 1-4 and sometimes also mesotarsomeres 3-4 medially with a distinct (in protarsi) or only suggested (in mesotarsi) dentiform process. Pro- and mesotibiae with spines at outer margins relatively large and usually more numerous than in other species (e.g. three, rarely four larger spines in protibiae and six to eight medium to large sized spines in mesotibiae).

Median lobe of aedoeagus ( Figs 13-17 View Figs 13-17 ) small and stout, apex widely rounded without apical lamella. Internal sac with characteristic fine structures, consisting of patches of fine triangular spines medially and apically. Female hemisternite and basal and apical segment of gonocoxa as figured ( Fig. 23 View Figs ).

C o m p a r i s o n s P. brunneus nov.sp. ( Figs 4-6 View Figs 4-6 ) differs from all other members ( Figs 1-3 View Figs 1-3 , 7-12 View Figs 7-9 View Figs 10-12 ) of the Psychristus discretus group by the general appearance; the light brown ground colour; the large and broad head (HW/PW> 0.81) with strongly protruding eyes and distinctly prolonged and curved mandibles; the mentum with epilobes less projecting and mental tooth relatively large; ligular sclerite triangularly acuminate at apex; the shape of pronotum, with less strongly punctate base; the lack of a setiferous puncture in posterior half of elytral interval 3; protarsomeres 1-4 in both sexes ventrally with a dentiform process medially, in females protarsomeres also more distinctly dilated, spines at outer margins of pro- and mesotibiae stronger and sometimes more numerous (e.g. protibiae with three to four spines, instead of two to three, and mesotibiae with seven to eight spines) and the shape and internal structures of median lobe of aedoeagus ( Figs 13-17 View Figs 13-17 ).

The species differs additionally from P. discretus by having the pronotal anterior margin arcuate, with anterior angles more widely rounded and not or only weakly projecting; the elytral surface somewhat depressed and less convex; the elytra narrower and shorter relative to pronotum (EW/PW <1.46, EL/PL <2.89), with humeri more distinctly angulate and humeral tooth more distinctly developed and often slightly projecting (in discretus usually no more than suggested) and antennae longer relative to elytra (see ratio AL/EL> 0.63). From P. shibatai it is also separated by the comparatively longer elytra (EL/EW> 1.50), which are narrower relative to pronotum (EW/PW <1.46) and the antennae, which are longer relative to elytra (AL/EL> 0.63). For additional characters separating P. brunneus from P. dentatus see above.

E t y m o l o g y: The Latin adjective brunneus, meaning brown, refers to the brown body colour of the species.

D i s t r i b u t i o n: The known distribution area ( Fig. 26 View Figs 26-27 ) reaches from northeast

Pakistan in the west across northern India and northern Thailand to north and eastern Laos.

In addition to the above-mentioned distribution, a single record is known from the Tanimbar Islands in the Wallacea region. This record is very far from any other known record and must therefore be confirmed by other collections from the same area.

D i s c u s s i o n: Within the genus Psychristus the species has been placed into the P. discretus group of the subgenus Psychristus s.str., because it displays all the characters defining these taxonomic units. However, this placement is provisional, because within the subgenus or partly even within the genus, P. brunneus has some unique features of probably higher taxonomic value, e.g. mandibles distinctly prolonged, shape of mentum and ligula modified, protarsi 1-4 in both sexes ventrally with a dentiform process and male protarsi without typical adhesive hairs. However, a detailed cladistic analysis of all members of the genus should be done to find apomorphic character states useful for defining monophyletic species groups. Depending on the proved sister group relations then the subgeneric classification of Psychristus should be revised, and if appropriate, a formal supraspecific rank (e.g. subgenus) can be proposed for P. brunneus .