Type species: Pycnoscelus obscurus Scudder, 1862 [= P. surinamensis (Linnaeus, 1758)], by monotypy.

Remarks: The genus was described as monotypical, on the basis of a single specimen that Scudder (1862) believed to be a male. However, it is evident from the original description that this specimen is actually a larva. Later, P. obscurus was synonymized with P. surinamensis by Princis (1964).

Pycnoscelus surinamensis is a parthenogenetic (thelytokous) species with a worldwide distribution. The closely related P. indicus is a bisexual species distributed in South and South-East Asia (Roth, 1998). Pycnoscelus indicus is evidently most closely related to P. surinamensis. I previously considered these as parthenogenetic and bisexual forms of a single species (Anisyutkin, 2002), but meanwhile I changed my view and follow Roth (1967, 1974, 1998) in regarding them as two distinct species: P. indicus and P. surinamensis.

Species included: Those given in Beccaloni (2014) [P. aurantia Hanitsch, 1935, P. conferta Walker, 1869, P. femapterus Roth, 1998, P. gorochovi Anisyutkin, 2002, P. indicus (Fabricius, 1775), P. janetscheki Bey-Bienko, 1968, P. micropterus Hanitsch, 1931, P. nigra (Brunner von Wattenwyl, 1865), P. rothi Anisyutkin, 2002, P. semivitreus Princis, 1967, P. striatus (Kirby, 1903), P. surinamensis (Linnaeus, 1758), P. tenebrigera (Walker, 1868) and P. vietnamensis Anisyutkin, 2002] plus P. schwendingeri sp. nov.

Material examined: ZIN, without accession number; 5 females of unknown provenance, reared in captivity in Saint Petersburg in 2017.

Additions to description of female (Figs 1–5): Based on specimens listed above, the description of Roth (1998) can be supplemented with the following details.

Somatic characters of female (Figs 1–2): Abdomen without visible glandular specializations; spiracle-bearing outgrowths of tergite VIII weakly expressed (Fig. 1). Anal plate (tergite X) wider than long, its hind margin widely rounded and with a weak medial notch (Fig. 1). Cerci short, flatten, with segments solidly connected but distinct (Fig. 1). Genital plate wide, with a distinct pair of paramedian emarginations on hind margin (Fig. 2). Paraprocts mostly membranous, bordered with a thin angulate sclerite on anterior and posterior side (Fig. 3, par.).

Ovipositor and adjacent structures (Figs 3–5): Intercalary sclerite absent. Tergal processes of abdominal segment VIII wide and reduced, not reaching paratergites of tergite VIII, fused with basivalvula (Fig. 3, teVIII.); tergal processes of abdominal segment IX fully developed (Fig. 3, teIX.). Gonangulum distinct, well sclerotized (Figs 3–5, gg.). All valves of ovipositor mostly membranous, only partly sclerotized. First valves large, membranous at apex, with numerous setae along inner side (Fig. 4, v.I.). Base of 2nd and 3rd pairs of valves as in Fig. 5, sclerotized lobes well developed (Figs 4–5, pl.). Anterior arch of second valvifer slightly angulate, as in Fig. 5, a.a. Second valves of ovipositor small, completely hidden under 1st ones (Fig. 4, v.II.). Third valves of ovipositor (gonoplacs) wide (Figs 3–4, v.III.). Basivalvula developed as a pair of slightly asymmetrical, widely rounded and partly sclerotized plates (Figs 3–5, bsv.). Vestibular structure in shape of membranous pad (Fig. 3, vs.). Brood sac (Fig. 3) without sclerotized structures.

Material examined: MHNG, without accession number; male holotype (genital complex in prep. 110817/01); THKN-12/04: Cambodia, Siem Reap Prov., Kbal Spean (13°41′04″N, 104°01′10″E), 200 m, semi-evergreen forest; 27.VI.2013; leg. P. Schwendinger.

Etymology: This species is named in honor of Dr Peter Schwendinger, collector of the holotype of this species and curator of the Arthropoda collections of the Muséum d'histoire naturelle de Genève.

Description:

Somatic characters of male (holotype): General colour yellowish brown, with scattered black spots (Figs 6–7); facial part of head contrastingly coloured (Fig. 7); eyes black; antennae greyish; pronotum, tegmina and abdominal sternites with black spots; legs yellow, partly darkened. Surfaces smooth and lustrous, antennae with proximal 8–10 segments lustrous, the remaining segments dull; pronotum, tegmina, mostly in proximal half, and, to a lesser degree, facial part of head with distinct punctuation. Head slightly longer than wide, with transverse impression between antennal sockets (Figs 7, 12); ocellar spots small but distinct; distance between eyes about equal to eye length; distance between antennal sockets about 2.5 times scape length (~0.6 mm); approximate length ratio of 3rd-5th segments of maxillary palps 1.1 : 1.0 : 1.2. Pronotum as in Figs 6, 13; cranial margin widely rounded, caudal one distinctly angulate. Tegmina and wings slightly abbreviate, reaching abdominal apex (Figs 6–7). Tegmina with widely rounded apex (Fig. 6), sclerotized in costal field; venation simplified and slightly obliterated along cranial margin; Sc thickened (well visible on ventral side of tegmen); R, M and CuP weak; anal field with obliterated venation. Hind wings membranous, shorter than tegmina, with simplified venation. Fore tibiae distinctly thickened distally (Fig. 14). Anterior margin of fore femora of armed type C, with single apical spine (Fig. 14). Tibial spines well developed. Structure of hind tarsus (Fig. 15): metatarsus about as long as other tarsal segments combined, with large euplantula; spines absent; claws symmetrical, simple; arolium distinct, about half as long as claw. Fore and mid tarsi similar to hind tarsi, but segments comparatively shorter. Abdomen without visible glandular specializations; tergite VIII with distinct spiracle-bearing outgrowths (Figs 16–17), large medial and two smaller oval lateral membranous areas; sternite VIII large, plate-like and weakly sclerotized (Fig. 18). Anal plate (tergite X) weakly sclerotized and asymmetrical (Figs 16–17). Cerci short, with distinct segments. Paraprocts of blaberi-type, with curved hook on right paraproct and with membranous area at cranio-medial angles of left paraproct (Fig. 17, par.). Hypandrium asymmetrical (Figs 19–20), with caudal margin weakly concave, hook at caudolateral angle well sclerotized (Fig. 20, h.); left stylus absent, right one in shape of elongated triangle.

Genitalia of male holotype (Figs 20–26): Right phallomere (R+N): caudal part of sclerite R1T well sclerotized, widely rounded (Fig. 21, c.p.R1T); bristles absent; R1T nearly straight; R2 weakly curved; R3 elongated (Figs 21–22); R4 small, not fused with other sclerites; R5 absent; R1T and R2 cranially prolonged into large sclerotized plate. Sclerite L2D (L1) divided into basal and apical parts (Fig. 24); basal part robust, widened cranially (Fig. 24, b.L2D); “apical sclerite” with small teeth at caudal margin (Figs 23–24, ap. scl.); bristles absent; “dorsal outgrowth” present (Figs 23–24, d.o.). Sclerite L3 (L2d) without basal subsclerite (Figs 25–26); “folded structure” weakly developed, without bristles (Fig. 26, f.s.); apex of L3 with “small tooth” (Figs 25–26, s.t.); groove hge absent. Sclerite L4U (L3d) divided into two parts (Fig. 25). Female: Unknown.

Measurements (in mm): Head length 2.6, head width 2.5; pronotum length 4.0, pronotum width 5.8; tegmen length 10.8, tegmen width 3.9.

Comparison: Pycnoscelus schwendingeri sp. nov. belongs to the indicus species-group (Roth, 1998) judging from the structure of its right stylus. This species-group includes nine species (Roth, 1998; Anisyutkin, 2002): P. conferta, P. femapterus, P. indicus, P. janetcheki, P. nigra, P. surinamensis, P. gorochovi, P. vietnamensis and P. rothi. The new species readily differs from all species of the indicus species-group by a contrastingly coloured pronotum and facial part of head (Figs 6–7). From P. indicus, P. nigra, P. janetsheki, P. conferta and P. femapterus the new species differs by a distinctly asymmetrical, i.e. emarginated at right side (Figs 16–17), anal plate. The shape of the anal plate is somewhat similar in P. gorochovi, P. vietnamensis, P. rothi and P. schwendingeri sp. nov., but these species can be readily differentiated by the shape of the apical part of sclerite L2D of the male genitalia (compare figs 26–28 in Anisyutkin, 2002 and Figs 23–24 of present paper).

Material examined: MHNG, without accession number; 1 male (genital complex in prep. 110817/02) and 18 larvae; W. Malaysia, N. of Kuala-Lumpur, Batu Caves; November 1976; collector unknown, probably Dr Brigitte Köpchen.

Description: On the basis of the newly examined male specimen the description of Roth (1998) can be supplemented with the following details.

Somatic characters of male: General colour yellowish brown (Figs 8–11), pronotum and facial part of head darker; eyes black. Surfaces smooth and lustrous, antennae with lustrous proximal 6–7 segments, remaining segments dull; pronotum and tegmina, mostly in proximal half, with distinct punctuation. Head as in Figs 9, 27, slightly longer than wide, with transverse impression between antennal sockets; ocellar spots small but distinct; distance between eyes about equal to eye length; distance between antennal sockets about 2.5 times scape length (~0.6 mm); approximate length ratio of 3rd-5th segments of maxillary palps 1.3 : 1.0 : 1.3. Pronotum as in Figs 8, 28. Tegmina and hind wings distinctly abbreviate, not reaching abdominal apex. Fore tibiae distinctly thickened distally (Fig. 29). Anterior margin of fore femora of armed type C, with single apical spine (Fig. 29). Tibial spines well developed. Structure of hind tarsus similar to that of P. schwendingeri sp. nov., but metatarsus slightly longer than other segments combined, distally bordered with pair of “additional spines”; 2nd and 3rd tarsal segments with “additional spines” on their outside; arolium distinct, smaller than one half of claw length. Fore and mid tarsi similar to hind tarsi, but segments comparatively shorter. Abdomen without visible glandular specializations; tergite VIII with distinct spiracle-bearing outgrowths (Figs 10–11, 30) and large medial membranous area; sternite VIII large, plate-like. Anal plate (tergite X) weakly sclerotized, very weakly asymmetrical (Figs 10, 30). Cerci short, with distinct segments (Figs 10, 30). Paraprocts of blaberi-type, similar to those of P. schwendingeri sp. nov. Hypandrium asymmetrical, irregularly sclerotized (Figs 11, 31–32), with caudal margin convex, hook at posterolateral angle well sclerotized (Fig. 32, h.); left stylus absent, right one in shape of wide plate.

Male genitalia (Figs 33–38): Right phallomere (R+N): caudal part of sclerite R1T well sclerotized, widely rounded (Fig. 33, c.p.R1T); bristles absent; R1T nearly straight; R2 weakly curved; R3 elongated, similar to that of P. schwendingeri sp. nov.; R4 plate-like, not fused with other sclerites; R5 elongated. Sclerite L2D (L1) divided into basal and apical parts (Fig. 35); basal part robust (Fig. 35, b.L2D); “apical sclerite” with recumbent bristles (Figs 34–35, ap. scl.); “dorsal outgrowth” weak (Figs 34–35, d.o.). Sclerite L3 (L2d) with basal subsclerite (Figs 36–38, b.L3); “folded structure” present, without bristles (Figs 36–38, f.s.); apex of L3 with “small tooth” (Figs 36–38, s.t.); groove hge absent. Sclerite L4U (L3d) divided into two parts (Fig. 36).

Measurements (in mm): Head length 3.4, head width 3.2; pronotum length 5.0, pronotum width 6.5; tegmen length 10.9, tegmen width 5.0.