Pteroplistes bruneiensis Tan, Gorochov & Wahab, 2019

Tan, Ming Kai, Gorochov, Andrei V., Wahab, Rodzay Bin Haji Abdul, Japir, Razy & Chung, Arthur Y. C., 2019, New taxa of crickets (Orthoptera: Grylloidea: Gryllinae, Phaloriinae and Pteroplistinae) from northern Borneo (Belait and Sandakan), Zootaxa 4661 (1), pp. 101-117 : 108-112

Pteroplistes bruneiensis Tan, Gorochov & Wahab , new species

( Figs. 6–9 )

Material examined. Holotype (male, BRU.19.55), Brunei Darussalam, Belait District, along Jalan Labi at Teraja , abandoned fruit plantation, N4.28479, E114.41841, 46.7± 5.2 m, 1 March 2019, 2033 hours, on tree trunk, coll. M.K. Tan & H. Yeo ( UBDM).

Paratypes: 2 males, 1 female: 2 males ( BRU.19.59, 60), same locality as holotype, N4.28487, E114.41817, 28.7±4.9, 2 March 2019, 1906 hours, on tree trunk, coll. M.K. Tan & H. Yeo ; 1 female (KB.17.79), Brunei Darussalam, Temburong District, Kuala Belalong Field Studies Centre, along Ashton Trail , ridge dipterocarp forest, N4.54714, E115.15715, 90.1± 7.3 m, 26 July 2017, 2102 hours, on foliage, coll. M.K. Tan (all ZRC) .

Diagnosis. The new species differs from all known species of Pteroplistes by the following characters: rachis (=guiding rod) in male genitalia almost straight, rather short and broad, located nearly perpendicular to the longitudinal axis of genitalia, and with posterior (dorsal in other congeners) process strongly bifurcated.

Comparison with congeners. In bifurcated posterior (dorsal) process of rachis, the species is similar to Pteroplistes acinaceus Saussure, 1877 from Malay Peninsula, Pteroplistes borneoensis Gorochov, 2004 from Sandakan (Sabah) and Sarawak and Pteroplistes malaccanus Gorochov, 2018 from Malay Peninsula, but this bifurcated part is with wider distance between its apices in P. acinaceus , and rachis is more straight and shorter than in P. borneoensis and P. malaccanus . The new species also differs from P. borneoensis in the lobules on male anal plate longer and with thinner proximal part, rachis almost straight and directed downwards, and upper process of rachis fairly broad (in lateral view).

The new species is also similar to Pteroplistes lagrecai Gorochov, 2004 from Mount Kinabalu (Sabah) in the rachis is almost straight and nearly perpendicular to the longitudinal axis of genitalia, and apex of posterolateral epiphallic lobes with an outward-pointing hook; but it differs from the latter in rachis fairly broad (in lateral view), upper process of rachis bifurcated, and apex of endoparamere less strongly curved backwards (i.e., this apex is located distinctly before the middle of genitalia; vs. at the middle of genitalia in P. lagraecai ).

Description. Body distinctly dorsoventrally compressed, with head and pronotum clearly pubescent ( Figs. 6A , 7A ). Head rostrum about as wide as scapus, with apex truncated (in dorsal view) ( Fig. 7C ); scapus rectangular; maxillary palpi elongated, with subapical segment longest, and with apical segment subequal to third segment in length but slightly wider apically (its apex obliquely truncated); eyes globular in dorsal view, elongated in lateral view; median ocellus small; lateral ocelli large, located near eyes; lateral ocelli small, located ventrally of median ocellus. Pronotal disc 1.1 times as wide as long, pubescent with strong hairs along anterior and posterior margins; anterior margin of disc slightly concave; posterior margin of disc straight ( Fig. 7C ). Pronotal lateral lobe 1.5 times as long as high, with ventral margin rising posteriorly ( Fig. 7A ). Fore tibia with minute oval tympana on both sides; fore and middle legs generally pubescent (especially along ventral margin), with a few stout setae usually located along dorsal margin; their tarsus with a row of stout setae on ventral surface; hind femur pubescent and flattened, without ventral spines; hind tibia also pubescent, with about 18 small and stout spines on each dorsal side, with 2 long ventral apical spurs on inner margin and 4 shorter other apical spurs; hind basitarsus with about 7 inner and 7 outer denticles. Tegmen ( Fig. 7B ) not pubescent, extending beyond abdominal apex, with dorsal field longer than lateral field, and with five oblique veins in harp area; tegminal mirror large, about as wide as long, with anterior margin angular, with posterior margin widely rounded, and with two parallel dividing veins which gently-curved and located close to one another; anal area of tegmen longer than length of mirror; lateral field wide, with 20 branches of Sc and about 10 cross-veins (often indistinct) between R and M ( Fig. 7A ); R and M mostly parallel, strongly converging towards the apex; hind wings slightly surpassing tegmina ( Fig. 6A ). Metanotal gland with anterior half having dorsal convexity; this convexity large, transverse, non-pubescent, with two punctures in the middle near the anterior margin, with lateral parts bulbous, and with posterior margin concave forwards and distinctly carinated; posterior half of this gland pubescent, with small bulbous lobules laterally, and with posterior edge having obtuseangled median tubercle ( Fig. 7C ). Anal plate tongue-shaped, with a small (short) triangular median lobule near the anterior margin and lamellate lateral lobules more or less similar to those of P. lagrecai (see Gorochov, 2004: Fig. 27) ( Fig. 7D ). Subgenital plate trapezoidal, about as long as wide anterior margin wide, lateral margins tapers slightly posteriorly, posterior margin deeply emarginated. Male genitalia as shown in Fig. 8 : epiphallus (ep) almost H-shaped, with strongly transverse median part, moderately long posterolateral lobes and very long anterolateral parts; posterolateral epiphallic lobes (p.ep) lamellate, but with strongly sclerotized inner margins as well as basal and distal parts only (lateral parts of these lobes, except for distal parts, membranous); distal parts of these lobes hook-like apically, with apices of these hooks directed aside; rachis (ra) very strongly sclerotized, almost straight and stout in lateral view, and directed almost perpendicularly downwards in relation to the longitudinal axis of genitalia; apical part of rachis tapering into an acute apex, laterally compressed when viewed ventrally; anterior margin of rachis straight when viewed laterally; apical part of rachis pointed, looking slightly less sclerotized; posterior margin of rachis, when viewed laterally, substraight, slightly sinuated after posterior (dorsal) process; this process almost perpendicular to rachis but somewhat curved in lateral view, strongly bifurcated, with each branch slightly hooked and pointing posteriorly and slightly dorsad (i.e., backwards and slightly upwards); endoparameres (en) strongly sclerotized, slender, with anterior parts curved ventrad and posteriorly, and with posterior parts almost touching each other. Formula (f) complicate shape, with long lateral projections: one strongly sclerotized, curved ventro-posteriorly and forked at the apex (each apical branch with acute apex pointing posteriorly); another projection produced anteriorly, slightly less sclerotized, lamellate and with obtuse apex; rami (r) strongly S-shaped, widened and lamellate in the middle part.

Female ( Fig. 6B ). Similar to males, but dorsal tegminal field with 9–10 longitudinal branches (some of these branches in middle part of tegmen more or less S-shaped) and rather numerous cross-veins (in proximal and middle parts of tegmen, these cross-veins obliquely situated, and cells between them largest in middle part of tegmen), lateral tegminal field with 11–13 branches of Sc and 12–13 cross-veins (often indistinct) between R and M ( Fig. 9A ), metanotal gland absent, and anal plate unspecialised. Subgenital plate large, transverse, broadly rounded, with apex having a minute posteromedian notch ( Fig. 9B ). Ovipositor typical of genus: elongated, reaching middle of hind tibia, and with margins smooth; ventral margin gently curved upwards in distal half; dorsal margin also very gently curved upwards but with small and almost obtusely angular convexity before distal part; distal part of ovipositor (after this convexity) straight and tapering into an acute apex ( Fig. 9C ).

Colouration. Body generally brown ( Fig. 6 ). Head and pronotum dark brown ( Fig. 7A ); scapus and pedicel red brown; gena, maxillary palpi and clypeus brown to red brown ( Fig. 7A ). Tegminal dorsal field with black pattern near anterior area, chord area and behind mirror; lateral tegminal field pale brown with brown veins ( Fig. 7B ). Fore and middle legs with coxa brown, femur pale, tibia and tarsus brown; hind femur mostly pale with spot of black pattern on the dorsal edge before middle, at apical third and knee area of inner surface (knee of this femur dorsally dark brown, ventrally red brown); hind tibia and tarsus brown, with distal part darker, and with black spines ( Fig. 6 ). Thoracic and abdominal segments yellow brown to brown.

Measurements (in mm). Male holotype BL = 17.7; HL = 2.7; PL = 3.2; PW = 3.4; TL = 15.5; TW = 6.6; HWL = 16.3; HFL = 12.2; HTL = 7.8. Female paratype BL = 14.5; HL = 2.8; PL = 3.5; PW = 4.0; TL = 13.9; TW = 4.0; HWL = 15.5, HFL = 21.3; HTL = 8.6; OL = 9.5.

Etymology. The species is named after the type locality, Brunei Darussalam.

Natural history. Numerous individuals, including nymphs, were found dwelling on the tree trunk.

Figures

FIGURE 6. Pteroplistes bruneiensis Tan, Gorochov & Wahab, sp. nov. male (A) and female (B) in dorsal view.

FIGURE 7. Pteroplistes bruneiensis Tan, Gorochov & Wahab, sp. nov. male habitus in lateral view (A); tegmen in dorsal view (B); head, pronotum and metanotal gland in dorsal view (C); anal plate in dorsal view (D).

FIGURE 8. Pteroplistes bruneiensis Tan, Gorochov & Wahab, sp. nov. male (holotype) genitalia in dorsal (A), ventral (B) and lateral (C) views.

FIGURE 9. Pteroplistes bruneiensis Tan, Gorochov & Wahab, sp. nov. female: body in dorsal view (A); subgenital plate in ventral view (B); ovipositor in lateral view (C).