Parallelissus fuscus Meng, Qin & Wang, 2020

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 : 66-70

Parallelissus fuscus Meng, Qin & Wang, 2020

Figs 1 , 33–34

Parallelissus fuscus Meng, Qin & Wang, 2020 in Zhang et al. (2020): 436 (keyed in Chinese), 437 (described), 606 (keyed in English), 607 (described in English), fig. 183 (head, wings, male terminalia), pl. XXXVI, g–i (habitus).

Diagnosis

Parallelissus fuscus Meng, Qin & Wang, 2020 can be recognized by

(1) the basically variegated brown colour of the body ( Fig. 33A, C );

(2) the subrectangular pygofer in lateral view ( Fig. 34A );

(3) the posterior margin of the capitulum of the gonostylus in lateral view with distinct hump at mid height (ca, G – Fig. 34A );

(4) the pair of lateroventral processes of aedeagus tapering in distal portion projecting dorsocephalad (lvp – Fig. 34F–G ).

Material examined

VIETNAM • 1 ♂ (dissected, Figs 33–34 ), 2 ♀♀; 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 • 2 ♀♀; same collection data as for preceding; VNMN .

Note

The male holotype illustrated in Zhang et al. (2020) seems somewhat faded in colour and illustration, hence description of a fresh specimen is provided here ( Fig. 33 ). The terminalia ( Fig. 34 ) of the male from Vietnam show the aedeagus with lateroventral processes (lvp) directed dorsocephalad, which is not the case in the specimen from China illustrated in Zhang et al. (2020) but these processes are movable and this must be kept in mind when identifying species in this group.

Supplementary description

MEASUREMENTS AND RATIOS. LT: ♂ (n = 1): 5.4 mm, ♀ (n = 4): 5.9 (5.6–6.2); LT/BB = 2.00; LTg/BTg = 2.30; LW/BW = 1.25; BV/LV = 2.00; LF/BF = 0.90.

HEAD ( Fig. 33A–D ). Vertex twice as broad as long in midline, variegated brown, paler towards basal angles and along median obsolete carina; margins carinate; anterior margin moderately, angularly convex, posterior one deeply, roundly concave and lateral ones subparallel; disc excavate. Side of head yellowish brown. Frons subquadrate, widest in ventral ⅓, variegated brown, darker along upper margin and with 2 paler markings in middle; incomplete median carina limited to upper half, yellowish; row of yellowish tubercles (sometimes double row) along dorsal and lateral margins; lateral margins sinuate, upper margin concave, frontoclypeal suture incurved. Clypeus pale brown, darker towards apex. Labium brown with last segment longer than broad, and shorter than penultimate. Scape short, ring-shaped, black; pedicel cylindrical, moderately elongate, brown.

THORAX ( Fig. 33C–D ). Variegated brown. Pronotum ⅔ the length of mesonotum in midline with obsolete, yellowish median carina; anterior margin carinate, strongly, angularly protruding cephalad in middle; very narrow on sides, behind eyes; posterior margin weakly bisinuate; disc weakly concave with yellowish tubercles, forming row along posterior margin; paranotal lobes yellowish brown with dark brown marking behind eye and yellowish tubercles along lateral margin. Mesonotum rather short with yellowish median carina, and longitudinal carina on each side; one yellowish tubercle at each external angle; apex of scutellum yellowish. Tegulae pale brown.

TEGMINA ( Fig. 33A–C ). Convex, variegated brown and yellowish, with irregular darker patches in basal portion of clavus, in basal portion of radial and median cells and along transverse area about ⅔ of tegmen length; 1.65 times as broad as long when taken together in dorsal view; distinct hump laterally on ScP vein at about basal ⅓; subcoriaceous with longitudinal veins raised and dense reticulum of slightly raised transverse veinlets in distal half; costal area rather wide; hypocostal plate absent; costal margin broadly rounded, apical margin rounded. Venation: ScP+RA and RP fused along short common stem; ScP+RA long, reaching to about 4/5 of tegmen length, RP very long, nearly reaching to apical margin of tegmen; MP forked at about half length, MP 1+2 forked near apex of tegmen, MP 3 unforked; CuA forking slightly after MP, CuA1 and CuA2 unforked; clavus closed, elongate, reaching to about distal 4/5 of tegmen, Pcu and A1 fused at middle of clavus.

HIND WINGS ( Fig. 33E ). Well developed, with 3 distinct lobes ( Sarimini type) more or less equal in width; blackish brown with paler area in basal half between costal margin and CuA, around angle between Pcu-A1 and A2 lobes, and between A2 and posteroclaval margin. Venation: ScP+R and CuA furcate, MP simple, second branch of CuA and CuP fused distally, Pcu and A1 fused on basal half, Pcu biforked and A2 simple; one transverse vein between second branch of ScP+R and MP, and between MP and first branch of CuA.

LEGS ( Fig. 33A–D ). Slender and moderately long, yellowish with the following dark brown: preapical ring and apical ring on pro- and mesofemora, apical ring on pro and mesotibiae, large marking on dorsal portion of metafemora, and apex of spines of metatibiae and metatarsi. Metatibiae with 2 lateral spines on distal ½ and 6 apical spines; first metatarsus with row of 8 minute teeth along posteroventral margin, limited with larger tooth on each side. Metatibiotarsal formula: (2) 6 / 10 / 2.

MALE TERMINALIA. Pygofer (Py – Fig. 34A–C ) about 2.3 times as high as long at mid-height, subrectangular in lateral view, with anterior margin weakly concave, upper margin nearly horizontal and posterior margin weakly rounded; about 1.4 times as high as wide in caudal view. Gonostyli (G – Fig. 34A, C–E ) (in lateral view) concave, rather short with capitulum strongly developed dorsad, projecting posteriorly to capitulum in distinct lobe rounded apically; capitulum (ca) with wide neck, with anterior margin prolongating that of body of gonostylus, evenly, moderately sinuate when taken together, posterior margin with 2 distinct humps; moderately developed preapical lateral tooth, apical hook projecting cephalad; in caudal view strongly tapering at base of capitulum, inner margin of capitulum bisinuate. Aedeagus ( Fig. 34F–K ) symmetrical, moderately curved dorsad (in lateral view); pair of strong, elongate lateroventral processes (lvp) directed mesocephalodorsad, distinctly tapered and curved dorsad after basal ⅓, then evenly tapering to pointed apex (see notes); dorsal lobe of periandrium (dl) slightly narrowing in middle portion, with median ridge in distal portion, projecting posterodorsad apically with rather deep narrow median notch, lateral margins recurved dorsad in distal portion, generating sinuate ribbon-like process directed cephalad and with minute teeth on dorsal margin; ventral lobe (vl) dorsoventrally flattened, slightly shorter than dorsal lobe and well separated from latter, with lateral margin bisinuate in ventral view, expanded laterally in middle portion and with distal portion spatulate, with apical margin rounded; phallus membranous. Anal tube (An – Fig. 34A–C ) curved posteroventrad, dorsoventrally flattened behind anal opening (in basal ⅓), strongly elongate; in dorsal view, about 2.65 times as long in midline, as wide, suboval with lateral margin weakly sinuate in basal portion and apical margin rounded.

Biology

Parallelissus fuscus 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

China: Guangxi, Shiwandashan Forest; 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. 33. Parallelissus fuscus Meng, Qin & Wang, 2020, dissected ♂ (RBINS). A. Habitus, dorsal view. B. Habitus, ventral view. C. Habitus, lateral view. D. Habitus, perpendicular view of frons. E. Right hind wing.

Fig. 34. Parallelissus fuscus Meng, Qin & Wang, 2020, ♂ (RBINS), terminalia. A–C. Pygofer, anal tube and gonostylus. A. Lateral view (flipped). B. Dorsal view. C. Caudal view. D–E. Left gonostylus. D. Caudal view. E. Dorsocaudal view. F–K. Aedeagus and connective. F. Left lateral view. G. Left dorsolateral view. H. Ventrocaudal view. I. Ventral view. J. Dorsal view. K. Anterodorsal view. Abbreviations: see Material and methods.