Pseudochoutagus nuichuanus, Constant & Pham & Nguyen, 2025

Constant, Jérôme, Pham, Thai-Hong & Nguyen, Hoai Thu Thi, 2025, Two new Parahiraciini planthoppers from Central Vietnam in the genera Gelastyrella and Pseudochoutagus (Hemiptera, Fulgoromorpha, Issidae), ZooKeys 1257, pp. 1-24 : 1-24

Pseudochoutagus nuichuanus sp. nov.

Figs 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15

Type material.

Holotype ♂, Vietnam • Khanh Hoa Province, Nui Chua National Park , 30 Jun. – 8 Jul. 2025; 11°46'28"N, 109°11'55"E; 50–700 m; J. Constant, J. Bresseel, L. Semeraro, Trung Thanh Vu leg.; VNMN -E.:000.016.110 ; VNMN.

Paratypes, Vietnam • 2 ♀♀; same data as for holotype; VNMN -E.:000.016.111 - 112; VNMN • 1 ♂; same data as for holotype; I. G.: 35028; RBINS • 3 ♀♀; Khanh Hoa province, Nui Chua National Park , 3–6 Oct. 2024; 11°46'28"N, 109°11'55"E; 50-700 m elev.; J. Constant, J. Bresseel, L. Semeraro, Hoai T. T. Nguyen leg.; I. G.: 34893; RBINS .

Diagnosis.

The species is closest externally to P. rubens Gnezdilov & Constant, 2012 (see illustrations in Constant 2021: fig. 5), and P. trungi Constant & Pham, 2024 (see illustrations in Constant and Pham 2024 b: figs 28–30), but P. rubens differs by the dark, reddish brown body (variegated brown washed with yellowish in P. nuichuanus sp. nov.), and both P. rubens and P. trungi differ by the more robust, relatively shorter and very weakly curved cephalic process (process more slender, relatively longer and distinctly upcurved in distal portion in P. nuichuanus sp. nov.).

Description.

Measurements and ratios: LT: ♂ (n = 2): 9.4 mm; ♀ (n = 5): 10.3 mm (10.2–10.5). LT / BB = 2.5; LTg / BTg = 2.0; LW / BW = 1.5; LV / BV = 2.8; LF / BF = 2.6.

Head (Figs 9 A – C , 10 A – D ): strongly elongated anteriorly in a cephalic process slightly sinuate with distal portion upcurved (in lateral view); vertex variegated brown; distinctly longer in midline than broad before eyes (about 2.8 times), widening from base to anterior margin of eyes, tapering beyond eyes to narrowly rounded apex, median and lateral carinae distinct but rather weak; posterior margin moderately incurved. Side of head brown but coloured as vertex on sides of cephalic process. Frons entirely blackish brown, distinctly darker than sides of head and vertex, slightly coriaceous; lateral carinae reaching apex, median carina distinct in distal 2 / 3; elongate, widest slightly anterior to eyes, roundly tapering towards clypeal suture; clypeal suture distinctly rounded. Clypeus black-brown, weakly elevated medially in distal portion. Labium brown with last segment longer than broad, and shorter than penultimate. Antennae dark brown; scape short, ring-shaped; pedicel bulbous.

Thorax (Figs 9 A, C , 10 A – D ): pronotum coloured as vertex; about 2 / 3 the length of mesonotum in midline; anterior margin weakly carinate, sinuate and moderately protruding anteriorly between eyes, with peridiscal carinae indistinct; posterior margin nearly straight; median carina obsolete; weak impressed point on each side of median line; weak blunt, tubercles along anterior and posterior margins; paranotal lobes (lateral view) moderately broad, with posteroventral angle rather narrowly rounded. Mesonotum coloured like vertex with longitudinal carinae very weak and blunt; 2 weakly impressed points on disc; tip of scutellum pale yellow. Tegulae brown.

Tegmina (Figs 9 A – C , 14 ): variegated brown, washed with yellowish in basal portion, irregular black transverse band just beyond midlength; at about basal 1 / 3, more or less distinct transverse band of white wax, apical 1 / 3 covered in white wax, basal 1 / 3 with scattered small points of white wax; veins concolorous except in distal 1 / 3, where dark brown; subcoriaceous with longitudinal veins distinct (elevated in distal 1 / 3 of tegmen) and with dense reticulum of veinlets; shape elongate and convex with sides broadly rounded, widest around half-length, about twice as long, as broad; narrowly rounded apically. Postclaval margin widely rounded and notched at apex of clavus. Clavus closed, reaching about 3 / 5 of tegmen.

Venation: ScP + R forking close to base after short common stem, ScP + RA and RP single, running more or less parallel to costal margin in a large basal portion; MP forked slightly before basal 1 / 3, resulting veins unforked, running more or less parallel; CuA weakly diverging from claval joint; Pcu and A 1 fused at distal 1 / 4 of clavus, resulting Pcu + A 1 reaching claval joint before apex of clavus; dense reticulum of veinlets, especially after basal 1 / 3; veinlets distinctly raised in basal 2 / 3 (adding to coriaceous aspect).

Hind wings (Fig. 10 E ): black-brown, slightly paler along costal margin in basal half; venation concolorous (slightly darker); wing broader than tegmen and deeply bilobed at CuP; costal margin sinuate; CuP-Pcu-A 1 lobe broadly rounded along postclaval margin and about 1.3 times as wide as Sc-R-MP-CuA lobe, both about the same length and apically rounded; A 2 lobe moderately reduced and narrow.

Venation: longitudinal veins ScP-R-MP-Cu well distinct; Pcu and A 1 separated; numerous cross-veins; A 2 rather weak.

Legs (Fig. 9 A – E ): moderately elongate, slender; yellow-brown with pro- and mesotarsi and distal portion of metafemora, brown; spines of hind legs apically black; femora wider than corresponding tibiae; metatibiae with 2 lateral spines in distal half and 7 apical spines. Metatibiotarsal formula: (2) 7 / 9–10 / 2.

Abdomen (Fig. 9 B ): yellowish brown with dark brown mediobasal marking (stronger on basal segments).

Terminalia ♂: (Figs 11 , 12 ): pygofer (Fig. 11 B – E ) about 2.2 × as high as long in lateral view, with anterior and posterior margins subparallel, sinuate; subcircular in caudal view; posterior margin with posterodorsal angle nearly right and dorsal margin straight; in dorsal view, posterior margin very deeply and roundly excavate. Gonostyli (Fig. 11 B – E ) (in lateral view) longer than high (without dorsal capitulum), tapering posteriorly in a distinct lobe narrowly rounded apically and concave; capitulum with wide neck, directed posterodorsad, with distal portion obliquely concave, smooth and ended in a tooth curved laterodorsad and with outer margin under lateral laminate projection, strongly concave in caudal view. Aedeagus (Figs 11 G – L , 12 ) symmetrical, distinctly curved dorsad (in lateral view), longer and wider than ventral lobe of periandrium; dorsal lobe of periandrium with narrow, tapering median process and with pair of posterolateral pointed processes recurved cephalad, lateroventral margin distinctly sinuate and partly covered by ventral lobe, together forming an incomplete tube around aedeagus ss; ventral lobe of periandrium evenly widening posterior to lateroventral processes of aedeagus, with apical margin rounded; aedeagus sensu stricto elongate, bifid, with pair of massive, elongate lateroventral processes evenly curved mesocephalad, originating slightly beyond half length, more or less regularly tapering to narrowly pointed apex not reaching base of aedeagus. Connective elongate, weakly curved, with massive tectiductus with dorsal crista. Anal tube (Fig. 11 A, F ) dorsoventrally flattened, in dorsal view spatulate with apical margin roundly emarginate (bisinuate), about 2.0 × as long in midline, a wide; basal portion narrow, widening to strong sinuation at level of anal opening; distal portion weakly, roundly tapering to lateroposterior rounded angles; in lateral view, strongly curved near base, then nearly straight; anal opening at about midlength.

Terminalia ♀ (Fig. 13 ): hind margin of sternum VII with massive, rather short, apically rounded median process.

Etymology.

The species epithet nuichuanus refers to Nui Chua National Park in Khanh Hoa Province, where the new species was discovered.

Biology.

One specimen was found sitting on a tree trunk in a rather dry area (Figs 14 A , 15 A ), and the others were swept from dense bushes (Fig. 15 B ) in subtropical evergreen forest. When disturbed, they tend to run to escape, to the other side of the trunk they sit on, rather than to jump away.

Distribution.

Vietnam, Binh Thuan Province, Nui Chua National Park (Fig. 8 ).

Figures

Figure 8. Distribution map of Gelastyrella vuquangensis sp. nov. and Pseudochoutagus nuichuanus sp. nov.

Figure 9. Pseudochoutagus nuichuanus sp. nov., paratype ♀ (RBINS). A. Habitus, dorsal view; B. Habitus, ventral view; C. Habitus, lateral view; D. Metatibia and metatarsus, ventral view; E. Distal portion of metatibia and metatarsus, ventral view.

Figure 10. Pseudochoutagus nuichuanus sp. nov., paratype ♀ (RBINS). A. Head and thorax, dorsal view; B. Frons, perpendicular view; C. Head and thorax, lateral view; D. Head and thorax, anterolateral view; E. Right hind wing.

Figure 11. Pseudochoutagus nuichuanus sp. nov., holotype ♂ (VNMN). A. Anal tube, lateral view; B – E. Pygofer and gonostyli; B. Lateral view; C. Posterolateral view; D. Caudal view; E. Dorsal view; F. Anal tube, dorsal view; G – L. Aedeagus; G. Dorsal view; H. Ventral view; I. Lateral view; J. Caudal view; K. Laterodorsal view; L. Lateroventral view.

Figure 12. Pseudochoutagus nuichuanus sp. nov., holotype ♂ (VNMN). A – D. Periandrium; A. Lateral view; B. Lateroventral view; C. Dorsal view; D. Caudal view; E – H. Aedeagus ss; E. Lateral view; F. Caudal view; G. Dorsal view; H. Ventral view.

Figure 13. Pseudochoutagus nuichuanus sp. nov., paratype ♀ (RBINS), terminalia.

Figure 14. Pseudochoutagus nuichuanus sp. nov., live specimen in Nui Chua National Park, 4 October 2024. A. In situ on tree trunk; B – D. Photographed in cage.

Figure 15. Habitat of Pseudochoutagus nuichuanus sp. nov. in Nui Chua National Park, 4 October 2024. A. Dry area; B. Evergreen forest.