Orientostichus Sciaky et Allegro, 2013

Fedorenko, D. N., 2023, A review of Pterostichus subgenus Orientostichus (Coleoptera: Carabidae: Pterostichini) from Indochina, with description of new species, Russian Entomological Journal 32 (2), pp. 155-170 : 156-161

Subgenus Orientostichus Sciaky et Allegro, 2013

Type species: Pterostichus prattii Bates, 1890 .

DIAGNOSIS. Rather large-sized apterous species from China and northern Indochina, recognizable chiefly by terminal labial and maxillary palpomere subtriangular, distinctly broader apically than basally; mandibular scrobe without longitudinal sulcus at bottom; and tergite VII with a dense preapical fringe of longer setae in female ( Figs 11–12 ). The species otherwise share characters as follows: pronotal base bisulcate, with sulci mostly joining along base, on each side; elytral parascutellar striole mostly missing, interval 3 with single or no seta behind middle (see ‘Redescription’ below), USS continuous, consisting of multiple and dense US. Metepisternum short. Tarsi not laterally carinate or dorsolaterally sulcate, tarsomeres 3 and 4 mostly with more than two-rowed, long and dense, ventral setae. Abdominal sternite VII mostly modified in male into a well-developed median carina ( Figs 13–18 ). Many species also share elytral intervals more or less distinctly cross-striated on sides toward apex ( Figs 10–12 ).

Aedeagus in lateral view geniculate or nearly so, with apical 3/5 median lobe bent much ventrad (at an acute angle); right paramere short, flat, somewhat hastate. Everted and inflated internal sac slightly bent to the left, with a characteristic Λ- shaped sclerite on left side, this sclerite being entire or divided into two.

Both female sternite VIII ( Figs 53, 55, 57 ) and laterotergite IX with apical margin conspicuously crenulate or serrate and setulose between serrations; gonocoxite IX spatulate ( Figs 58–60 ): short, wide, asetose, with apex widely rounded.

REDESCRIPTION. BL 14–27 mm. Body ( Figs 1–9 ) shiny black, slightly iridescent or not, sometimes dull from coarse microsculpture in female. Dorsal microsculpture meshed, isodiametric on head, transversely rectangular and more or less wide on pronotum. Elytral microsculpture isodiametric to very transverse or consisting of dense transverse lines depending on species, sometimes granulate in female or imperceptible; striae at bottom with meshes coarse and slightly longitudinal, reflexed lateral margin with microsculpture coarse isodiametric to superficial longitudinal.

Body setation as for many Pterostichus : head bisetose above each eye, submentum bisetose, mentum with two proximate setae at base of median tooth, labial palpomere 2 bisetose; pronotum quadrisetose; elytron without or with parascutellar seta; abdominal sternites IV–VI with one pair of obligatory medial setae; fe 1 posterior face trisetose; cx 3 bisetose laterally (inner seta missing), tr 3 asetose, fe 3 bisetose along anteroventral edge, tarsomere 5 mostly setose ventrally.

Head medium-sized, eyes convex, rather small to medium-sized; gena about two fifths as long as eye, meeting neck at very obtuse angle. Neck constriction almost imperceptible. Two supra-ocular setae inserted just inside deep supra-ocular groove. Frontal sulci mostly short, not reaching the level of anterior supra-ocular setae, diverging, shallow or moderately deep and impunctate; frons smooth or with faint, parallel or slightly diverging, striae between eyes. Clypeus bisetose, apically subsinuate; labrum slightly sinuate, sexsetose. Antennae submoniliform, reaching or slightly surpassing pronotal base, antennomeres 4–11 pubescent; scape and pedicel each with a long seta, dorsal or ventral, respectively; antennomere 3 without or with shorter extra setae between apical verticillate setae. Mandibles moderately long, obliquely striated on dorsal side. Mentum in front of base with a pair of extensive, more or less deep, round pits and two proximate setae at base of median tooth; this latter bifid and deeply longitudinally grooved, its lateral edges extended into fine ridges separating between lateral lobes and epilobes, these apically angulate or toothed. Submentum bisetose, outer setae missing. Labial palpomere 3 subtriangular, with apex obliquely truncate; maxillary palpomere 3 less so, sometimes fusiform.

Pronotum quadrate to subcordate; sides rounded to sinuate in front of basal angles, finely beaded, with lateral bead slightly flattened and broadened toward base in some species, without or with a distinct sublateral line inside fine lateral groove. Basal angles slightly acute to obtuse and rounded. Base mostly distinctly sinuate at middle, bisulcate on each side. Inner basolateral sulci long and deep, outer ones short- er, either joining these latter along base or separate, with a more or less convex area in between and a costate fold between outer sulcus and lateral groove. Apex truncate to sinuate; apical bead fine, broadened medially, obliterate in about middle third. Basal and apical transverse impressions indistinct or almost so. Median line fine yet moderately deep, obliterate apically and/or basally. Disc rather smooth, base mostly impunctate or vaguely punctate. Lateral setae situated in lateral groove.

Elytra elliptic, broadest at or just behind middle, with apices rounded separately each. Base oblique, humeri distinct, blunt to rounded, without teeth. Basal ridge entire, convex apicad, humeral angle right and sharp to very obtuse and rounded. Preapical sinuation moderately deep to very shallow, internal preapical plica well-developed, visible in dorsolateral view, sometimes much reduced. Striae entire, deep or very deep, impunctate or finely punctate, 7th starting from just outside to slightly inside humeral angle. Parascutellar striole mostly totally reduced, in some species varying individually from missing to short. Intervals mostly convex, more so before apex, 1st merged in lateral edge (apical bead) at sutural angle, 2nd separate apically, either 7th, 5th and 3rd confluent apicad in succession or 3rd and 7th joining apically. Interval 8 basally, as well as 7th and 8th just before preapical sinuation, very narrow, costate or subcarinate. Reflexed lateral margin outside stria 9 concave or flat, often vaguely catenate, more distinctly so down the middle, or with a blunt carina (additional interval) in apical half. Parascutellar seta present or ( P. curtatus Fairmaire, 1886 ; P. perlutus Jedlička, 1938 ; P. pulcher Sciaky et Allegro, 2013 ) missing. Interval 3 behind middle without or with seta d3, or ( P. pulcher ) intervals 3, 5, and 7 catenulate, each broken by 5–7 setae in links. Stria 7 with two distant preapical setae, sometimes intermediate seta present. USS consisting of multiple US, 21–37 in number.

Prosternum with a shallow median groove between cx 1; prosternal process in ventral view more or less flat, apically rounded, not or indistinctly beaded, in lateral view rectangular or nearly so, with apex rounded or not; declivity in caudal view wide, either costate or flat to barely concave, without or with distinct lateral edges or fine beads, respectively. Mesoventrite neither carinate nor toothed laterally, anterior declivity flat or longitudinally concave. Metepisternum as wide at anterior margin as long at outer margin or wider than long. Abdominal sternites finely beaded along sides. Mesepisternum, metepisternum, sides of metaventrite and of abdominal sternites II–IV densely and rather finely punctate, underside otherwise smooth. Abdominal urite VIII moderately transverse in female ( Figs 52–57 ): tergite slightly rounded at apical margin, basal apodemes rather short, as long as or slightly longer than wide, and slightly pigmented; sternite with apical margin conspicuously crenulate or serrate and setulose between serrations, basolateral apodemes large, as wide as long, central desclerotized (depigmented) area ω- shaped.

Legs moderately strong. Ti 1 slightly dilated apicad, with three spinules at posterolateral edge, two apical and one preapical, and 1–2 spinules at apex of posterior ridge. Tr 3 apically rounded or blunt, about half as long as fe 3; ta 2 about as long as ti 2, ta/ti2L 0.86–1.13, ta 3 slightly shorter than ti 3, ta/ti3L 0.74–0.93; tarsomere 1 barely shorter to distinctly longer than tarsomeres 2 and 3 combined, mstm1/23L 0.88– 1.25, mttm1/23L 0.87–1.17. Meso- and metatarsomeres 1 and 2 with outer (anterior) ventrolateral sulcus only (lateral carina and dorsolateral sulcus missing). Leg chetotaxy: fe 2 with two anteroventral setae and 2–5 anterodorsal setae in apical half; ti 2 with 4–6 and ti 3 with 0–4 setae along outer margins; tarsomeres 1–4 with one pair of latero-apical setae, mesotarsomeres 1–3 and metatarsomeres 1–2 or 1–3 with one pair of dorso-apical setae; tarsomere 5 with 1–4, mostly 3, pairs of ventral setae. Tarsal ventral setae varying between species in density as well as in shape, from rather sparse, spiniform (more so on tarsomeres 1 and 2), arranged into two rows, to sparse, spiniform, two-rowed on tarsomere 1, combined with more than two-rowed, long and dense, brush-like setae, on tarsomeres 3, 4 and often also 2.

Aedeagus ( Figs 19–51 ): apex long, narrow, dorsoventrally flattened and slightly twisted. Everted and inflated internal sac rather simple in shape, bent slightly to the left, with a fairly large right basal bulb, without or with left basal bulb. Left distal bulb replaced with (modified into) two sclerites, large medial and narrow lateral, these mostly merged into a Λ- shaped sclerite.

Female genitalia and reproductive tract ( Figs 58–60 ): gonosubcoxite IX and gonocoxite IX glabrous. Bursa copulatrix large, obtrapezoidal, broader anteriorly than posteriorly; with dorsobasal wall more or less distinctly sclerotized. Spermatheca differentiated, rather short, angled; seminal canal short, 2–2.5 times as long as slightly arcuate receptacle, with no basal sclerite or bulbous structures; gland ductspermathecal junction just in the corner.

Secondary sexual characters: Male protarsomeres 1–3 dilated, with biserial squamo-setae on ventral side (vs. toothed at ventro-apical angles in female); ti 2 toothed at base of longer apical movable spur. Abdominal tergite VII without (♂) or with (♀) a row of multiple, long, more or less dense, preapical setae; sternite VII bi- (♂) or quadrisetose (♂). As usual in Pterostichus and many other carabids, elytra are barely longer and slenderer in male than in female.

DISTRIBUTION. The subgenus includes 14 described species and many undescribed ones from China, including Taiwan, and adjacent parts of Indochina (northern Burma, northern Thailand, and northern Vietnam).

HABITS AND HABITATS. Member species of the genus inhabit cloudy forests, occuring at the altitudes of 300– 1.800 m ( P. prattii Bates, 1890 [ Sciaky, Allegro, 2013]) or 2.100 m ( P. semirugosus ( Andrewes, 1947) and P. ferreroi Straneo, 1989 ), or 1.200 –1.400 m ( P. gallopavo Sciaky et Wrase, 1997 ), or 2.800 –3.100 m ( P. pulcher Sciaky et Allegro, 2013 ). Specimens of the other examined species have been collected at 1.500 –3.400 m altitudes in China or 1.650 – 2.100 m in Vietnam.

COMMENTS. In erecting Orientostichus , Sciaky & Allegro [2013] pointed out its some similarity to the subgenera Pseudethira Sciaky, 1997 or Sinoreophilus Sciaky, 1996 . I consider Orientostichus to be more closely allied to Steropanus Fairmaire, 1888 , while recognizing the latter as hardly separable from Pseudethira , and it seems to me that Wraseiellus Shi et Sciaky, 2013 , is the next relative of Orientostichus .

As far as Orientostichus and Steropanus are concerned, both are similar in pronotal shape and structure. The two taxa also share similar body setation, including cx 3 bisetose, tr 3 asetose, etc., combined with many, certainly apotypic characters such as the bisetose submentum, the asulcate mandibular scrobe, the terminal labial palpomere dilated apically, elytral USS continuous and consisting of multiple US, the parascutellar striole much reduced or missing, the elytral interval 8 often attenuated and thence subcarinate before and behind, the elytral discal setae reduced much in number, and the tarsi distinctive, not laterally sulcate, with the ventral setae being more or less brush-like and the dorso-apical setae tending to be present on the basal three segments, instead of basal two, as is characteristic of many other Pterostichus . Furthermore, aedeagi are similar in general except only that right paramere is mostly longer in Steropanus than in Orientostichus . This also is true of the internal sac, which is rather simple in its general shape and has either a well-developed preapical sclerite or ( P. pseudoglymmiger Fedorenko, 2020 ) bulbs apparently homologous to the sclerites observed in Orientostichus .

On the other hand, pregenital segments, genitalia and reproductive tract are much less similar in females of the taxa compared. The similarity is due only to (1) no basal sclerite of the seminal canal found, (2) gonosubcoxite IX glabrous, and (3) gonocoxite IX short and wide, with ensiform setae reduced to enlarged ventral ones ( Steropanus ) or totally ( Orientostichus ). Steropanus otherwise has spermatheca welldifferentiated, angulate, including seminal canal long and receptacle clavate, and a well-developed bulbous structure at spermathecal-oviduct junction, which is peculiar to many other Pterostichus . The reproductive tract of Orientostichus has spermatheca differentiated yet rather short, with no bulbous structure at its base, which character combination may suggest remote relationships between Orientostichus and the Platysma lineage, including Sinoreophilus .

All the species from Indochina are here arranged into two species groups whose members share the elytra with parascutellar seta and intervals barely to conspicuously cross-striated toward apices. The prattii -group mostly includes larger-sized and rather slender species such as P. semirugosus ( Andrewes, 1947) ; P. ferreroi Straneo, 1989 ; P. matalini sp.n.; P. makarovi sp.n.; and probably P. distinctissimus Jedlička, 1940 . The lesticoides -group includes four species, which are very similar in appearance.

Figures

Figs 10–18. Pterostichus: 10, 15 — P. matalini sp.n.; 11, 14 — P. prattii, from Moupin, China; 12 — Pterostichus sp. from China; 13 — P. curtatus; 16 — P. pseudolesticoides sp.n.; 17 — P. ferreroi; 18 — P. makarovi sp.n.; 10–12 — apices of elytra and abdomen, dorsal aspect; 13–18 — abdominal sternite VII in male, left lateral view. Not to scale. Рис. 10–18. Pterostichus: 10, 15 — P. matalini sp.n.; 11, 14 — P. prattii, иЗ Moupin, Китай; 12 — Pterostichus sp. иЗ КитаЯ; 13 — P. curtatus; 16 — P. pseudolesticoides sp.n.; 17 — P. ferreroi; 18 — P. makarovi sp.n.; 10–12 — вершины надкрылий и брюшка, дорЗально; 13–18 — стернит VII брюшка саца, вид слева. БеЗ масштаба.

Figs 52–60. Abdominal urites VIII–IX and reproductive tract in female: 52–53, 58–59 — Pterostichus prattii; 54–55 — P. matalini sp.n.; 56–57, 60 — P. laevistriatus sp.n.; 52, 54, 56 — tergite VIII; 53, 55, 57 — sternite VIII; 58–60 — urite IX and reproductive tract; 52–58, 60 — ventral aspect; 59 — dorsal aspect; bc — bursa copulatrix; ov — common oviduct; rp — receptacle; sgd — spermathecal gland duct; sc — seminal canal. Scale bars 1 mm. Рис. 52–60. Уриты VIII–IX брюшка и репродуктивный тракт самки: 52–53, 58–59 — Pterostichus prattii; 54–55 — P. matalini sp.n.; 56–57, 60 — P. laevistriatus sp.n.; 52, 54, 56 — тергит VIII; 53, 55, 57 — стернит VIII; 58–60 — урит IX и репродуктивный тракт; 52–58, 60 — вентрально; 59 — дорЗально; bc — копулЯтивнаЯ сумка; ov — непарный Яйцевод; rp — семеприемник; sgd — проток желеЗы сперматеки; sc — семепровод. Масштаб 1 мм.

Figs 1–3. Dorsal habitus: 1 — Pterostichus makarovi sp.n., paratype ♀; 2–3 — P. matalini sp.n., paratypes from Phan Xi Pang Mt or Bat Xat NP. Рис. 1–3. Габитус дорЗально: 1 — Pterostichus makarovi sp.n., паратип ♀; 2–3 — P. matalini sp.n., паратипы с г. Фансипан и иЗ Национального парка Батсат.

Figs 4–6. Dorsal habitus: 4 — Pterostichus lesticoides, holotype; 5 — P. prattii, ♀ from Chengkou; 6 — P. ferreroi, paratype ♂. Рис. 4–6. Габитус дорЗально: 4 — Pterostichus lesticoides, голотип; 5 — P. prattii, ♀ иЗ Chengkou; 6 — P. ferreroi, паратип ♂.

Figs 7–9.Dorsal habitus:7 — P. pseudolesticoides sp.n., paratype ♀; 8 — P. laevistriatus sp.n., holotype; 9 — P. tamdaoensis sp.n., holotype. Рис. 7–9. Габитус дорЗально: 7 — P. pseudolesticoides sp.n., paratype ♀; 8 — P. laevistriatus sp.n., голотип; 9 — P. tamdaoensis sp.n., голотип.

Figs 19–30. Aedeagus: 19–20, 25 — Pterostichus prattii, from Moupin, China; 21–22, 27 — P. matalini sp.n.; 23–24, 26 — P. ferreroi; 28 — P. makarovi sp.n.; 29 — P. pseudolesticoides sp.n.; 30 — P. lesticoides; 19–24 — median lobe; 25–30 — right paramere; 19, 21, 23, 25–30 — left lateral aspect; 20, 22, 24 — right lateral aspect. Scale bars 1 mm. Рис. 19–30. Эдеагус: 19–20, 25 — Pterostichus prattii, иЗ Moupin, Китай; 21–22, 27 — P. matalini sp.n.; 23–24, 26 — P. ferreroi; 28 — P. makarovi sp.n.; 29 — P. pseudolesticoides sp.n.; 30 — P. lesticoides; 19–24 — среднЯЯ долЯ; 25–30 — праваЯ парамера; 19, 21, 23, 25–30 — слева; 20, 22, 24 — справа. Масштаб 1 мм.

Figs 40–45. Aedeagus with everted and inflated internal sac: 40–41 — Pterostichus ferreroi, paratype; 42–43 — P. matalini sp.n.; 44– 45 — P. makarovi sp.n.; 40, 42, 43 — left lateral aspect; 41, 43, 45 — right lateral aspect. Scale bars 1 mm. Рис. 40–45. Эдеагус с вывернутым и раЗдутым внутренним мешком: 40–41 — Pterostichus ferreroi, paratype; 42–43 — P. matalini sp.n.; 44–45 — P. makarovi sp.n.; 40, 42, 43 — слева; 41, 43, 45 — справа. Масштаб 1 мм.

Figs 46–51. Aedeagus with everted and inflated internal sac: 46–47, 51 — Pterostichus pseudolesticoides sp.n.; 48 — P. ferreroi, paratype; 49 — P. matalini sp.n.; 50 — P. makarovi sp.n.; 46 — left lateral aspect; 47 — right lateral aspect; 48–51 — ventrobasal aspect. Scale bars 1 mm. Рис. 46–51. Эдеагус с вывернутым и раЗдутым внутренним мешком: 46–47, 51 — Pterostichus pseudolesticoides sp.n.; 48 — P. ferreroi, paratype; 49 — P. matalini sp.n.; 50 — P. makarovi sp.n.; 46 — слева; 47 — справа; 48–51 — вентробаЗально. Масштаб 1 мм.