Pseudocoruncanius obliquus, Constant & Pham, 2024

Constant, Jérôme & Pham, Hong Thai, 2024, Sixteen issid planthopper species in one day in Dong Son-Ky Thuong Nature Reserve in North Vietnam: Eight new species, one new genus and additional new records (Hemiptera: Fulgoromorpha: Issidae), European Journal of Taxonomy 919 (1), pp. 1-87 : 71-75

Pseudocoruncanius obliquus sp. nov.

urn:lsid:zoobank.org:act:92B20393-337C-4553-A393-53D2AB8BE801

Figs 1 , 35–36

Diagnosis

Pseudocoruncanius obliquus sp. nov. can be recognized by

(1) the colour of the frons with ventral ⅔ brown and dorsal ⅓ black with median transverse yellowish line ( Fig. 35D );

(2) the yellowish white oblique band in middle portion of tegmina, between cubital cell and vein MP 1+2 ( Fig. 35A, C );

(3) the black marking inside the apical cells of the tegmina ( Fig. 35C );

(4) the very elongate anal tube of the male in dorsal view, 2.9 times as long in midline, as wide (at widest point) (An – Fig. 36C );

(5) the gonostyli in lateral view with posterior portion forming a rather elongate lobe rounded apically (G – Fig. 36A );

(6) the dorsal lobe of periandrium evenly curved, without hump, in lateral view (dl – Fig. 36D ).

Differential diagnosis

The new species is close to both P. flavostriatus and P. nigrifrons . However, P. obliquus sp. nov. differs from P. flavostriatus by the oblique yellowish white band in middle portion of tegmina (white band in cubital cell extending straight to costal margin in P. flavostriatus – Zhang et al. 2020: pl. 36a, c), the anal tube 2.9 times as long in midline, as wide (at widest point) (2.7 times in P. flavostriatus – Zhang et al. 2020: fig. 181c) and the dorsal lobe of periandrium without hump in lateral view (distinct hump in P. flavostriatus – Zhang et al. 2020: fig. 181i). Furthermore, P. obliquus differs from P. nigrifrons by the brown ventral ⅔ of the frons (frons black in ventral ⅔ in P. nigrifrons – Gnezdilov 2022c: fig. 3), the black marking in the apical cells of the tegmina (cells brown in P. nigrifrons – Gnezdilov 2022c: fig. 1) and the anal tube 2.9 times as long in midline, as wide (at widest point) (2.3 times in P. nigrifrons – Gnezdilov 2022c: fig. 10).

Etymology

The species epithet ‘ obliquus ’ is a Latin adjective meaning ‘oblique’, and refers to the oblique pale band in the middle portion of the tegmina.

Type material

Holotype

VIETNAM • ♂ (dissected, Figs 35–36 ); Quang Ninh Province, Dong Son-Ky Thuong Nature Reserve ; 21°08′29″ N, 107°04′53″ E; 27 Aug. 2022; 550 m a.s.l.; secondary forest; GTI Project; J. Constant, J. Bresseel and L. Semeraro leg.; I.G.: 34.518; RBINS.

Paratypes

VIETNAM • 1 ♂ (dissected); same collection data as for holotype; VNMN.

Description

MEASUREMENTS AND RATIOS. LT: ♂ (n = 2): 6.4 mm (6.3–6.5); LT/BB = 2.43; LTg/BTg = 2.64; LW/BW = 1.36; BV/LV = 2.13; LF/BF = 0.66.

HEAD ( Fig. 35A–D ). Vertex flat, about 2.1 times as wide as long in midline, brown with margins weakly carinate; anterior margin convex, posterior one roundly concave and lateral weakly diverging anteriorly; obsolete paler median line. Side of head yellowish brown, darker in front of eye and along anteroventral margin; ocellus present under eye. Frons transverse, about 1.5 times as wide as long in midline, rugulose; brown with dorsal ⅓ blackish-brown and transverse pale yellowish, strongly contrasted band inside black-brown area, limited dorsally by weak peridiscal carina; pale yellowish tubercles between peridiscal carina and dorsal and lateral margins, in upper ⅓; median carina poorly distinct, restricted to upper ⅓; frontoclypeal suture incurved. Clypeus dark brown, darker towards apex, smooth. Labium brown with last segment longer than broad, and shorter than penultimate. Scape short, ring-shaped, dark brown; pedicel barrel-shaped, brown.

THORAX ( Fig. 35A, C–D ). Brown. Pronotum about ⅔ length of mesonotum, with weak, paler median carina with weakly impressed point on each side, and with rounded anterior margin carinate; disc more or less flat, weakly concave in anterior portion; some obsolete tubercles along anterior and undulate posterior margins; lateral fields of pronotum very narrow behind eyes; paranotal lobes weakly developed, rounded, pale brown (nearly translucent). Mesonotum triangular, slightly wrinkled with blunt median carina, distinct hump before scutellum and posterolateral margins carinate. Tegulae brown.

TEGMINA ( Fig. 35A–C ). Elongate, about 2.0 times as long as wide when taken together in dorsal view; brown with pale yellowish white band in cubital cell to half length, then obliquely reaching to vein MP 1+2, another elongate, yellowish white marking in distal ⅓ extending from median cell to posterior margin at veins MP 1 -MP 2 (can be fused with white band); radial cell sometimes darker, cells in middle portion of apical margin blackish; strong lateral hump in basal ⅓ at level of ScP+R vein, hiding costal margin in dorsal view; longitudinal veins and most cross veins raised; hypocostal plate moderately developed and narrow; clavus very elongate, closed. Venation: ScP+R dividing rather close to base; ScP+RA long, reaching costal margin at about 4/5 of tegmen length; RP very long, weakly curved, reaching to apical margin of tegmen; MP vein triforked with first fork around basal ⅓; MP 1+2 forked subapically, MP 3 simple, reaching apical margin; CuA vein first fork at about ⅔ of tegmen; veins Pcu and A1 fused near midlength of clavus, Pcu+A1 reaching apex of clavus.

HIND WINGS ( Fig. 35E ). Black brown; veins generally black, darker than background; well developed, with 3 distinct lobes ( Sarimini type) more or less equal in width; indentation between ScP-R-MP-Cu and Pcu-A1 lobes moderately deep. Venation: ScP+R and CuA furcate, MP simple, second branch of CuA and CuP fused distally, Pcu and A1 fused on basal half, Pcu and A2 simple; one transverse vein between second branch of ScP+R and MP and between MP and first branch of CuA; A2 not forked.

LEGS ( Fig. 35A–D ). Slender and relatively short; femora black, meso- and metafemora with brown median marking, metafemora with apical yellowish white ring; pro- and mesotibiae yellowish white with three black rings, one basal, one apical and one slightly before midlength; metafemora yellowish white with basal black ring and black suffused area in basal half; apex of spines of metatibiae and metatarsi black. Metatibiae with 2 lateral spines on distal ½ and 9 apical spines; first metatarsus with row of 7 minute teeth along posteroventral margin, limited with a larger tooth on each side. Metatibiotarsal formula: (2) 9 / 9 / 2.

MALE TERMINALIA. Pygofer (Py – Fig. 36A–C ) in lateral view about 2.25 times as high as long at maximum length (about ventral ⅓), curved, with anterior margin concave, upper margin straight, oblique and forming straight angle with posterior margin, and posterior margin rounded, more or less parallel to anterior one; about 1.4 times higher than wide in caudal view. Gonostyli (G – Fig. 36A–B ) (in lateral view) subtriangular, 1.2 times as high as long (including capitulum); anterior margin vertical, abruptly emarginate at base of neck of capitulum; ventral margin weakly sinuate; posterior portion forming rather elongate lobe rounded apically; posterodorsal margin obliquely sinuate, with distinct hump at base of neck of capitulum; capitulum (ca) rather narrow in lateral view, with elongate neck, a tooth in middle of anterior margin and one at anteroapical angle, dorsal portion curved anteromesad. Aedeagus ( Fig. 36D– I ) symmetrical, elongate and weakly curved dorsad (in lateral view); pair of slender, very elongate lateroventral processes (lvp) directed ventrocephalad in basal 3/5, then curved cephalodorsad, with apical portion curved mesad, apically pointed and visible from dorsal view; dorsal lobe of periandrium (dl) evenly curved in lateral view, without hump, lateral margins recurved dorsad in distal portion, generating a long undulate ribbon-like process directed cephalad and with minute teeth on dorsal margin; ventral lobe (vl) dorsoventrally flattened, shorter than dorsal lobe, narrow and rounded apically. Anal tube (An – Fig. 36A–C ) nearly straight in lateral view, abruptly narrowing at basal ¼ at level of anal opening, strongly elongate, about 2.9 times as long in midline, as wide in dorsal view, widest near anal opening, convex dorsally in cross-section and with apical margin narrowly rounded.

Biology

Paracoruncanius obliquus sp. nov. was collected in August, on lower vegetation and bushes, in moist evergreen tropical forest at about 550 m in altitude ( Fig. 1B ) in Dong Son-Ky Thuong Nature Reserve.

Distribution

Vietnam: Quang Ninh Province, Dong Son-Ky Thuong Nature Reserve ( Fig. 1A ).

Figures

Fig. 1. Dong Son-Ky Thuong Nature Reserve. A. Topographic map. B. Sampled habitat.

Fig. 35. Pseudocoruncanius obliquus sp. nov., dissected holotype, ♂ (RBINS). A. Habitus, dorsal view. B. Habitus, ventral view. C. Habitus, lateral view. D. Habitus, perpendicular view of frons. E. Right hind wing.

Fig. 36. Pseudocoruncanius obliquus sp. nov., holotype, ♂ (RBINS), terminalia. A–C. Pygofer, anal tube and gonostylus. A. Lateral view. B. Caudal view. C. Dorsal view. D–I. Aedeagus and connective. D. Left lateral view. E. Left dorsolateral view. F. Ventrocaudal view. G. Ventral view. H. Dorsal view. I. Anterodorsal view.Abbreviations: see Material and methods.