Sogana cysana sp. nov., a new tropiduchid planthopper from Chu Yang Sin National Park in Vietnam and key to Vietnamese species of the genus (Hemiptera: Fulgoromorpha: Tropiduchidae) Author Constant, Jérôme jerome.constant@naturalsciences.be(correspondingauthor). Author Pham, Thai Hong phamthai@vnmn.vast.vn. text Belgian Journal of Entomology 2020 2020-05-25 95 1 13 journal article 302784 10.5281/zenodo.13739330 679dbe7d-c37d-441a-93d5-53ee3004275a 2295-0214 13739330 B4E1BBAA-00DE-49EE-BFB1-DC82363391D5 Sogana cysana sp. nov. urn:lsid:zoobank.org:act: 99C20B3A-EF16-458C-BBB4-B5E2B6DDE439 ( Figs 2–5 ) ETYMOLOGY . The species epithet refers to the type locality, Chu Yang Sin National Park in Central Vietnam , with “cys” formed from the initials of “Chu Yang Sin” . Fig. 2. Sogana cysana sp. nov. , holotype ♂ (RBINS). A, habitus dorsal view. B, habitus, ventral view. C, habitus, perpendicular view of frons. D, habitus, lateral view. E, right tegmen. F, right posterior wing. G, head and thorax, dorsal view. H, head and thorax, laterodorsal view. I, head and thorax, lateral view. J, frons, perpendicular view. K, distal portion of left posterior leg, ventral view. TYPE MATERIAL . VIETNAM : holotype ♂ ( Figs 2 , 3 ): Coll. I.R.Sc.N.B. , Vietnam , Dak Lak prov. , Chu Yang Sin N.P. , 650-1000m , 12°27’24”N 108°22’15”E , 9-15.viii.2019 , GTI Project , Leg. J. Constant & J. Bresseel , I.G.: 34.048 (RBINS). Dissected , genitalia in glycerine, right hind wing mounted . Paratype ♀ : same collection data as holotype (VNMN) . NOTE . The female paratype was slightly damaged during collecting; especially, the broken apex of tegmina do not allow taking precise measurements, which are hence not given in description below. DIAGNOSIS . The species can be separated from the other Sogana species by the combination of the following characters: 1. Median carina of vertex departing from basal margin and limited to basal 1/2 of vertex ( Fig. 2 G–H ). 2. Frons with seven red transverse fasciae interrupted in the middle and linked on external side by longitudinal narrow red line; median carina reaching ventral margin and interrupted before dorsal margin ( Fig. 2 J ). 3. Clypeus pale yellow-brown with basal narrow red line on each side of median carina and sides black-brown apically ( Fig. 2 J ). 4. Tegmina with 13 apical cells ( Fig. 2 E ). 5. Anal tube elongate and narrow with apical margin emarginate with angles pointed in dorsal view ( Fig. 3 C ). 6. Aedeagus with dorsal process near base, divided in 2 lateral parts curved lateroventrally; right part less developed and ended in a tooth directed caudad; left part with 5 teeth directed caudad, second one from base much larger than others ( Fig. 3 E–I ). 7. Periandrium with 3 ventral processes near base, directed caudad, with right one slightly shorter than left one, and median one longer and laterally flattened ( Fig. 3 E–F, I–J ). Additionally, in the key proposed by LIANG & WANG (2008) combined with the additional couplet provided by CONSTANT (2010) , the new species runs to the couplet treating S. robustocarina Liang & Wang, 2008 and S. floreni Constant, 2010 , from which it can be very easily separated by the much less elongate vertex (LV/BV = 0.7; in S. robustocarina LV /BV = 1.1; in S. floreni LV /BV = 1.2) and by the shape of the anal tube apically emarginated and with pointed apicolateral angles (apical margin oblique in dorsal view in S. robustocarina and S. floreni ). DESCRIPTION . Measurements and ratios : LT: ♂ (n = 1): 8.8 mm . LTg/BTg = 3.5; LV/BV = 0.7; LF/BF = 1.5. Head : ( Fig. 2 G–J ) moderately elongate with apex rounded in dorsal view. Vertex excavate in middle; laterodiscal carinae oblique and strong, joining lateral margin near anterior margin of eye; area between laterodiscal carina and lateral margin of head flat, not excavate; median carina departing from caudal margin and limited to caudal 1/2 of vertex; vertex brown with anteromedian and two basolateral pale yellowish markings. Posterior face of head brown with median triangular pale yellowish marking. Frons straight in lateral view, with dorsal portion projecting anteriorly; median carina yellowish extending to apex of clypeus but not reaching dorsal margin of frons; frons pale yellow-brown with 7 transverse red bands on each side of median carina and linked on external side by longitudinal narrow red line; anterior margin of frons with 3 black-brown markings. Genae pale yellow-brown with narrow red line along dorsal margin, slightly anteriorly to eye and brown marking at base of antennae. Clypeus pale yellow-brown with basal narrow red line on each side of median carina and sides black-brown apically. Fig. 3. Sogana cysana sp. nov. , holotype ♂. A, pygofer, anal tube and gonostyli, left lateral view. B, pygofer, anal tube and gonostyli, right lateral view. C, pygofer, anal tube and gonostyli, dorsal view. D, left gonostylus, dorsal view. E, aedeagus, right lateral view. F, aedeagus, left lateral view. G, aedeagus, left laterodorsal view. H, aedeagus, dorsal view. I, aedeagus, left laterodorsal view. J, aedeagus, ventral view. An : anal tube – apa : apical process of aedeagus– cn : connective – dpa : dorsal process of aedeagus – esp : ear-shaped process of aedeagus – G : gonostylus – ldp : left dorsal process of aedeagus – pe : periandrium – Py : pygofer – vpp : ventral process of periandrium. Thorax : ( Fig. 2 G–J ) pronotum brown with yellowish markings on disc along carinae and behind eyes and darker markings basally on each side of median carina and on lateral fields; anterior margin bisinuate, rounded and carinate in middle; posterior margin bisinuate, emarginate in middle; median carina weakening anteriorly, extending only on caudal 2/3; black impressed point on each side of median carina; lateral carinae strong, yellowish; paranotal lobes rounded caudoventrally. Mesonotum pale yellow-brown with median carina and area comprised between discal carinae brown; discal carinae joining anteriorly, median carina rather smooth, not reaching anterior and posterior margins; 4 darker spots along posterior margin; scutellum brown with base black-brown; tegulae yellow-brown; lateral pleura of mesothorax with black-brown markings aligned with the markings on anterior coxae and clypeus. Tegmina: ( Fig. 2 A, D–E ) elongate, subhyaline with veins slightly darker; weak black-brown marking near base of postcostal cell; small brown patch at base of median cell; vein CuA2 dark brown on basal 1/6; elongate black-brown marking at apical angle of clavus including apex of vein Pcu+A1; vein PCu distally slightly forked and brown. Veins ScP+R and MP not forked before nodal line; CuA forked once before nodal line, at about basal 1/4 of tegmen. Four subapical and 13 apical cells; apical cells 6–9 infuscate on distal 2/3. Hind wings: ( Fig. 2 F ) hyaline with veins mostly dark brown, slightly notched at CuP apex; infuscate along vein CuP; 8 apical cells. Fig. 4. Sogana cysana sp. nov. , habitat in Chu Yang Sin National Park, August 2019. © Jérôme Constant. Legs: ( Fig. 2 A–D, K ) pale yellow-brown with base and apex of pro- and mesotibiae slightly infuscate; all femora with dark brown ante-apical ring, with irregular reddish marking in middle portion and with darker zone near base; base of pro- and mesocoxae brown; metatibiae with 3 lateral and 7 apical spines; first hind tarsomere with 9 apical spines. Metatibiotarsal formula: (3) 7/9/2. Abdomen : brown with terminalia darker. Fig. 5. Sogana spp. of Vietnam, distribution map. Terminalia ♂ : ( Fig. 3 ) pygofer with posterior margin roundly projecting on dorsal 3/ 4 in lateral view, 1.75 times higher than long in lateral view; anterior and posterior margins sinuate in lateral view ( Fig. 3 A–B ); posterior margin deeply V-shaped notched in dorsal view ( Fig. 3 C ). Gonostyli ( Fig. 3 A–D ) very elongate, about 4.25 longer than high in lateral view (measured without dorsal process), laterally compressed, with apex narrowly rounded; 3 hooked processes on dorsal margin slightly posteriorly to half length; basal one directed dorsally, middle one directed lateroventrally, caudal one directed centrally. Aedeagus ( Fig. 3 E–J ) assymmetrical, elongate and narrow, with a dorsal process near base, divided in 2 lateral parts, one left and one right, curved lateroventrally; right part of dorsal process less developed than left one, and ended in a tooth directed caudad; left part of dorsal process with 5 teeth directed caudad, second one from base much larger than others; periandrium with 3 ventral processes near base, directed caudad, with right one slightly shorter than left one, and median one longer and laterally flattened; dorsal ear-shaped process at apex, coiled on right side and covering 2 apical teeth directed dorsocaudad. Anal tube ( Fig. 3 A–C ) elongate and narrow, about 4.1 times longer than wide in dorsal view, slightly widening at level of epiproct in dorsal view, rather strongly sinuate with apex pointing ventrally in lateral view; apex emarginate in dorsal view with apical angles pointed; anal column situated slightly beyond half length. BIOLOGY . The specimens were collected in mountain tropical evergreen forest, at 800–1000m in altitude ( Fig. 4 ). DISTRIBUTION . Vietnam : Dak Lak Province , Chu Yang Sin National Park ( Fig. 5 ).