Ishiharanus pulchellus, Constant & Pham, 2025

Constant, Jérôme & Pham, Hong Thai, 2025, Issid planthoppers from Bach Ma and Phong Dien in Central Vietnam: (II) Tribe Hemisphaeriini (Hemiptera: Fulgoromorpha: Issidae), European Journal of Taxonomy 994 (1), pp. 1-76 : 53-60

Ishiharanus pulchellus sp. nov.

urn:lsid:zoobank.org:act:63484DED-CA93-4F5C-A0E8-20EDDDDC9DDE

Figs 2A , 3A , 4B , 5B , 29–35

Diagnosis

Ishiharanus pulchellus sp. nov. can be recognized by:

(1) its colour pattern with the dorsum more or less dark brown, with round yellow markings on the disc of the tegmina more or less distinct (according to colour form, not visible in dark specimens) and two pale yellow concentric lines parallel to posterior margin ( Figs 29A, C , 30A, C , 31A, C, G );

(2) the profemora pale yellow with basal and apical black brown rings ( Fig. 29B, D );

(3) the anal tube, in dorsal view, about 1.64 times as long in midline as wide, rather elongate with curved sides, and with apical margin moderately excavate and bisinuate (An – Fig. 32D );

(4) the lateroventral processes of the aedeagus showing two pointed, moderately curved, elongate portions, one directed cephalad and the other directed posteroventrad (lvp – Figs 32G–L , 33H–I ).

Differential diagnosis

The closest species, sharing some colouration characters of I. pulchellus sp. nov. (in its paler forms), is I. dinhanus sp. nov. which also shows pale yellow markings on the mesonotum and on tegmina. However, I. pulchellus is smaller: LT: ♂: 4.1–4.6 mm, ♀: 4.1–4.9 mm, as compared to LT: ♂: 5.1–5.2 mm, ♀ 5.5–5.9 mm in I. dinhanus ; I. pulchellus shows profemora pale yellow with basal and apical black brown rings ( Fig. 29B, D ), while in I. dinhanus they are dark brown, turning slightly paler towards apex ( Fig. 26B, E ), and I. pulchellus shows round yellow markings on the disc of the tegmina, more or less distinct (according to colour form, not visible in dark specimens), and two pale yellow concentric lines parallel to the posterior margin ( Figs 29A, C , 30A, C , 31A, C, G ), while in I. dinhanus the brown tegmina show three bright, elongate, pale yellow markings but no concentric lines parllel to the posterior margin ( Fig. 26A, D ). The two species also clearly differ in the shape of the lateroventral processes of the aedeagus, which in I. pulchellus show two pointed, moderately curved, elongate portions, one directed cephalad and the other directed posteroventrad (lvp – Figs 32G–L , 33H–I ), while in I. dinhanus they are rather short, apically pointed, strongly sinuate and generally directed cephalad (lvp – Fig. 27G–R ).

Etymology

The species epithet ‘ pulchellus ’ is a Latin adjective that means ‘small and beautiful, pretty’ and it refers to the small size and colour pattern of this species.

Material examined

Holotype VIETNAM • ♂ (dissected); Thừa Thiên-Huế Province, Bach Ma National Park , summit; 16°12′ N, 107°52′ E; 15–16 Jul. 2011; daytime collecting; J. Constant and J. Bresseel leg.; I.G.: 31.933; VNMN.

Paratypes VIETNAM • 4 ♂♂, 4 ♀♀; same collection data as for holotype; RBINS • 1 ♂, 1 ♀; same collection data as for holotype; VNMN • 1 ♀; Thừa Thiên-Huế Province, Bach Ma National Park ; 16°12′ N, 107°52′ E; 12–17 Jul. 2011; daytime collecting; J. Constant and J. Bresseel leg.; I.G.: 31.933; RBINS • 1 ♀; Thừa Thiên-Huế Province, Bach Ma National Park , [pheasant trail]; 16°12′ N, 107°52′ E; 10–16 Apr. 2017; J. Constant and J. Bresseel leg.; I.G.: 33.447; RBINS • 1 ♂; Thừa Thiên-Huế Province, Bach Ma National Park , summit; 16°11′18″ N, 107°50′56″ E; 1300–1400 m a.s.l.; 11–21 May 2023; J. Constant and L. Semeraro leg.; I.G.: 34.640; RBINS • 2 ♂♂, 4 ♀♀; Thừa Thiên-Huế Province, Bach Ma National Park , pheasant trail; 16°13′38″ N, 107°51′20″ E; 500–600 m a.s.l.; 10–20 May 2023; J. Constant and L. Semeraro leg.; I.G.: 34.640; RBINS • 1 ♀; Thừa Thiên-Huế Province, Bach Ma National Park ; 16.193° N, 107.853° E; 1250 m a.s.l.; 28 May–1 Jun. 2017; L. Bartolozzi, E. Orbach, V. Sbordoni, S. Bambi and A. Bandinelli leg.; numero Mag. 3089; MZUF • 1 ♀; Thừa Thiên-Huế Province, Bach Ma National Park, Xue Su ; [16°14′10″ N, 107°52′44″ E]; 2022; near stream; V.T. Trung leg.; VNMN • 1 ♀; Thừa Thiên-Huế Province, Bach Ma National Park, Rhododendron trail ; 19 Mar. 2023; 1158 m a.s.l.; V.T. Trung leg.; VNMN • 2 ♂♂, 1 ♀; Thừa Thiên-Huế Province, Bach Ma National Park , summit; 16°11′18″ N, 107°50′56″ E; 20 Oct. 2024; 1200–1400m; J. Constant, L. Semeraro, Hoai T.T. Nguyen leg.; I.G.: 34893; RBINS • 2 ♂♂, 3 ♀♀; Thừa Thiên-Huế Province, Bach Ma National Park, stairs going up to Hai Vong Dai ; 16°11′53.77″ N, 107°51′26.92″ E; 1272 m a.s.l.; 16 Sep. 2024; by net; Hoai T.T. Nguyen leg.; VNMN • 6 ♂♂, 2 ♀♀; Thừa Thiên-Huế Province, Phong Dien District; 16°30′27″ N, 107°16′05″ E; 350–400 m a.s.l.; 23 May 2023; J. Constant and L. Semeraro leg.; I.G.: 34.640; RBINS • 1 ♂, 2 ♀♀; Thừa Thiên-Huế Province, A Luoi, A Roang ; [16°07′04″ N, 107°24′19″ E]; 600–700 m a.s.l.; 4 May 2005; H.T. Pham leg.; Ho.1583, 1586, 1587; VNMN • 2 ♂♂, 4 ♀♀; Gia Lai Province, Kon Chu Rang Nature Reserve ; 14°28′28″ N, 108°32′27″ E; 600–1200 m a.s.l.; 13–20 Jul. 2018; GTI Project; J. Constant, J. Bresseel and X. Vermeersch leg.; I.G.: 33.769; RBINS • 1 ♂, 1 ♀; same collection data as for preceding; VNMN • 1 ♂, 1 ♀; Quang Tri Province, Dak Rong, Ta Rut ; [16°25′49″ N, 106°58′55″ E]; 500 m a.s.l.; 17 Jul. 2004; H.T. Pham leg.; Ho.0120, 121; VNMN • 1 ♂; Quang Nam Province, Nam Giang, Ta Bhinh ; [15°39′36″ N, 107°40′30″ E]; 100–250 m a.s.l.; 30 Apr. 2005; H.T. Pham leg.; Ho.1610; VNMN • 1 ♂; Quang Nam Province, Song Thanh National Park , Phuoc My District; 15°19′31″ N, 107°44′13″ E; 430–800m; 15–17 Oct. 2024; J. Constant, L. Semeraro and Hoai T.T. Nguyen leg.; VNMN • 1 ♂; same data as for preceding; I.G.: 34893; RBINS .

Description

MEASUREMENTS AND RATIOS. LT: ♂ (n = 5): 4.3 mm (4.1–4.6), ♀ (n = 5): 4.6 mm (4.1–4.9); LT/BB = 1.38; LTg/BTg = 1.60; LW/BW = 1.81; BV/LV = 1.84; LF/BF = 1.28.

HEAD ( Figs 29A–E , 30A–E , 31A–E ). Vertex broader than long in midline, bright pale yellow with anterior portion brown, with posterior margin weakly carinate; anterior margin convex, posterior one concave and lateral one subparallel; disc shallowly excavate. Side of head brown with pale yellow marking from insertion of antennae to genoclypeal suture. Frons elongate and smooth, chestnut brown with distinct pale yellow band along frontoclypeal suture. Clypeus chestnut to blackish brown, yellowish apically. Labium yellow brown with last segment longer than broad, black tipped and shorter than penultimate. Scape short, ring-shaped, brown; pedicel bulbous, brown.

THORAX ( Figs 29A, C–E , 30A, C–E , 31A, C–E ). Pronotum very short, about one third the length of mesonotum in midline; anterior and posterior margins carinate; disc concave with an impressed point on each side of median line, with extremely narrow lateral fields behind eyes; chestnut brown with ventral portion of paranotal lobes blackish brown. Mesonotum subtriangular, smooth, with carina along anterior margin; colour varying from black-brown, with median brown line in darker forms, to bright straw yellow with anterolateral angles brown in paler forms. Tegulae brown.

TEGMINA ( Figs 29A, C, E , 30A, C, E , 31A, C, E, G ). Strongly convex; about 1.1–1.2 times as long as broad when taken together in dorsal view; slightly concave at basicostal angle; slightly rugulose with dense reticulum of weakly raised veins and veinlets; main veins weakly distinct; dark brown with yellowish markings more or less developed depending on colour forms; usuallly one rather large basal marking, one round marking at midlength in dorsal portion and one anteapical along postclaval margin, the latter merging with apex of two subparallel, concentric lines following costal and apical margins, apical margin lined with black; in dark forms, pale markings may be reduced to only more external yellowish line along posterior margin; in pale forms, basal marking expanded and merging with first concentric line, leaving dark brown area forming a circle around dorsal yellowish spot.

HIND WINGS ( Figs 29F , 30F , 31F ). Brown, unilobed, with veins darker than cells; elongate, slightly shorter than tegmina. Venation reticulate with main longitudinal veins distinct basally (C, ScP+R, MP, CuA); numerous cross-veinlets. Anal area obsolete. Costal margin sinuate, cubital margin broadly rounded, distal margin rounded.

LEGS ( Figs 29A–B, G–H , 30A–B , 31A–B ). Elongate and slender; femora wider and shorter than corresponding tibiae; profemora pale yellow with basal and apical black brown rings; mesofemora pale yellow with posterior margin lined with black and anteapical incomplete black ring; metafemora brown, turning yellowish towards base and apex; pro- and mesotibiae pale yellowish with black line along externoventral carina and basal blackish ring; pro- and mesotarsi yellowish with black onychium; metatibiae yellowish, darker (brown) in middle portion with black tipped spines. Metatibiae with 2 lateral spines on distal half and 6 apical spines. Metatibiotarsal formula: (2) 6/ 8/ 2.

ABDOMEN. Yellow brown.

MALE TERMINALIA. Pygofer (Py – Figs 32A–D , 33A–F ) 2.1 times as high as long in lateral view; in lateral view, dorsal margin nearly horizontal, weakly sinuate followed posteriorly by a distinct oblique slope leading to distinct rounded angle protruding posterad at half height; ventral half oblique; more or less circular in caudal view. Gonostyli (G – Figs 32A–D , 33A–F ) in lateral view with ventral margin broadly rounded, posterior margin rounded, projecting caudad, dorsal margin oblique basally, prolongated to neck of capitulum; capitulum (ca) in lateral view with elongate, twisted neck, directed dorsocephalad, and with posterior margin strongly projecting posterad in a rounded straight angle, in caudal view subspatulate with upper angle rounded and directed mesodorsad, with small, rather blunt tooth at anterodorsal angle followed posterad by carina on external side strongly recurved cephalad and ending in a tooth projecting cephalad in lateral view, in caudal view with rather deep, round emargination under carina. Anal tube (An – Figs 32A–D , 33A–F ) elongate; in dorsal view about 1.45–1.60 times as long in midline as wide, regularly widening from base to basal ⅖, then subparallel (broadly rounded), with apical margin moderately bisinuate with middle portion upcurved; dorsoventrally flattened with posterior angles projecting posteroventrad; in lateral view, anal tube moderately curved posteroventrad; apical margin deeply, roundly emarginate in caudal view. Aedeagus curved posterodorsally and twisted, rather simple, asymmetrical ( Figs 32E–M , 33G–S ); lateroventral processes of aedeagus (lvp – Figs 32E–M , 33G–S ) showing two pointed, moderately curved, elongate portions, one directed cephalad and the other directed posteroventrad; ventral lobe of periandrium (vl) well developed and elongate but shorter than aedeagus, shifted to the right and regularly tapering towards roundly truncate apex; dorsal lobe of periandrium (dl) shorter than aedeagus; aedeagus largely membranous with pair of elongate, strong, pointed processes. Connective (co) well developed and curved, with tectiductus (te) well developed, with widely open foramen and well developed crista.

Biology

Ishiharanus pulchellus sp. nov. was collected from March to July and in September and October at altitudes between 100 and 1400 m a.s.l., in moist evergreen tropical forest. The specimens were sitting on lower vegetation and bushes on small branches, and more often on leaves, and seemed to prefer smooth leaves. The species was found at the collection sites/habitats ( Fig. 2A ) ‘pheasant trail’ ( Figs 2A (2), 3A) and ‘summit’ ( Figs 2A (5), 4B) in Bach Ma National Park, as well as in Phong Dien District ( Fig. 5B ).

Distribution

Vietnam, Central Annamites: provinces of Thừa Thiên-Huế (Bach Ma National Park, Phong Dien District, A Roang), Gia Lai (Kon Chu Rang Nature Reserve), Quang Nam (Ta Bhinh, Song Thanh National Park) and Quang Tri (Da Krong National Park) ( Fig. 35 ).

Figures

Fig. 2. Bach Ma National Park, habitats. A. Detailed map of the sampling areas (1 = ‘Yes Hue Eco’; 2 = ‘pheasant trail’; 3 = ‘low altitude’; 4 = ‘roadside’; 5 = ‘summit’; 6 = ‘near ranger station’. B. Typical habitat at ‘Yes Hue Eco’ sampling area, 17 May 2023.

Fig. 3. Bach Ma National Park, habitats. A. Typical habitat at ‘pheasant trail’ sampling area, 20 May 2023. B. Typical habitat at ‘low altitude’ sampling area, 15 May 2023.

Fig. 4. Bach Ma National Park, habitats. A. Typical habitat at ‘roadside’ sampling area, 21 May 2023. B. Typical habitat at ‘summit’ sampling area, 11 May 2023.

Fig. 5. Bach Ma National Park and Phong Dien District, habitats. A. Typical habitat at ‘ranger station’ sampling area, 18 May 2023. B. Typical habitat at Phong Dien sampling area, 23 May 2023.

Fig. 29. Ishiharanus pulchellus sp. nov., dissected holotype, ♂ (VNMN). A. Habitus, dorsal view. B. Habitus, ventral view. C. Habitus, lateral view. D. Habitus, perpendicular view of frons. E. Habitus, anterolateral view. F. Right hind wing. G. Right hind leg, ventral view. H. Metatarsus and apex of metatibia, ventral view.

Fig. 30. Ishiharanus pulchellus sp. nov., dissected paratype, ♂ (RBINS) from Bach Ma National Park, dark morph. A. Habitus, dorsal view. B. Habitus, ventral view. C. Habitus, lateral view. D. Habitus, perpendicular view of frons. E. Habitus, anterolateral view. F. Right hind wing.

Fig. 31. Ishiharanus pulchellus sp. nov., dissected paratype, ♂ (RBINS) from Kon Chu Rang National Park, pale morph. A. Habitus, dorsal view. B. Habitus, ventral view. C. Habitus, lateral view. D. Habitus, perpendicular view of frons. E. Habitus, anterolateral view. F. Right hind wing. G. Caudal view.

Fig. 32. Ishiharanus pulchellus sp. nov., dissected holotype, ♂ (VNMN), terminalia. A–D. Pygofer, anal tube and gonostyli. A. Left lateral view. B. Posterolateral view. C. Caudal view. D. Dorsal view. E–M. Aedeagus. E. Dorsal view. F. Ventral view. G. Left lateral view. H. Right lateral view. I. Left lateroventral view.J. Right lateroventral view. K. Left posterolateral view. L. Right posterolateral view. M. Caudal view. Abbreviations: see Material and methods.

Fig. 33. Ishiharanus pulchellus sp. nov., paratype, ♂ (RBINS) from Kon Chu Rang National Park, pale morph, terminalia. A–F. Pygofer, anal tube and gonostyli. A. Left lateral view. B. Posterolateral view. C. Caudal view. D. Dorsal view. E. Ventral view. F. Posterodorsal view. G–S. Aedeagus. G. Caudal view. H. Left lateral view. I. Right lateral view. J. Posteroventral view. K. Left laterodorsal view. L. Right laterodorsal view. M. Right posterolateral view. N. Left lateroventral view. O. Right lateroventral view. P. Left posterolateral view. Q. Dorsal view. R. Posterodorsal view. S. Ventral view. Abbreviations: see Material and methods.

Fig. 34. Ishiharanus pulchellus sp. nov., live specimens. A–D. In Bach Ma National Park, summit trail. A–B. 19 May 2023. C–D. 20 May 2023. E–H. Phong Dien District, 23 May 2023.

Fig. 35. Ishiharanus pulchellus sp. nov., distribution map.

Fig. 26. Ishiharanus iguchii (Matsumura, 1916). A–F. Dissected ♂ (RBINS) from Bach Ma. A. Habitus, dorsal view. B. Habitus, ventral view. C. Habitus, lateral view. D. Habitus, perpendicular view of frons. E. Habitus, anterolateral view. F. Right hind wing. G. Dissected ♂ from Cuc Phuong (RBINS), anterolateral view.

Fig. 27. Ishiharanus iguchii (Matsumura, 1916), ♂ (RBINS) from Cuc Phuong National Park, terminalia. A–F. Pygofer, anal tube and gonostyli.A. Lateral view.B. Posterolateral view.C. Caudal view.D. Dorsal view. E. Ventral view. F. Posterodorsal view. G–S. Aedeagus.G. Left lateral view. H. Right lateral view. I. Caudal view. J. Caudoventral view. K. Right laterodorsal view. L. Left posterolateral view. M. Left laterocaudal view. N. Left lateroventral view. O. Right lateroventral view. P. Right laterocaudal view. Q. Anterodorsal view. R. Dorsal view. S. Ventral view. Abbreviations: see Material and methods.