Keosarima armillata Constant, 2025

Constant, Jérôme & Pham, Hong Thai, 2025, Keosarima gen. nov., a new genus in the planthopper tribe Sarimini from Indochina (Hemiptera: Fulgoromorpha: Issidae), European Journal of Taxonomy 1007, pp. 35-56 : 40-47

Keosarima armillata Constant gen. et sp. nov.

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Figs 1–6

Diagnosis

Keosarima armillata Constant gen. et sp. nov. can be recognized by the very elongate shaft of the laterodorsal process of the periandrium, reaching nearly to base of aedeagus (sp – Fig. 3E ) and the lateroventral process of the aedeagus reaching to basal third of aedeagus (lvp – Fig. 4G ).

Differential diagnosis

The new species is close to Keosarima konkakinha gen. et sp. nov. but it shows a much longer shaft of the laterodorsal process of the periandrium, reaching nearly to the base of the aedeagus (limited to about halflength of the aedeagus in K. konkakinha ), and the shorter lateroventral process of the aedeagus more strongly sinuate and reaching to the basal third of the aedeagus (less sinuate and reaching to the basal fourth of the aedeagus in K. konkakinha ).

Etymology

The specific epithet ‘ armillata ’ is a Latin adjective meaning ‘ornamented with a bracelet’; it refers to the apical black ring of the pro- and mesotibiae.

Type material

Holotype

CAMBODIA • ♂ (dissected); Mondulkiri Province, Keo Seima Wildlife Sanctuary, near O Pam station; 12°11′39″ N, 107°01′01″ E; 14–24 Nov. 2018; J. Constant leg.; I.G.: 33.919; RBINS.

Paratypes

CAMBODIA • 25 ♂♂, 25 ♀♀; same data as for holotype; RBINS • 5 ♂♂, 9 ♀♀; same data as for holotype; RUPP-CEI .

Description

MEASUREMENTS AND RATIOS. LT: ♂ (n = 6): 5.3 mm (5.2–5.5), ♀ (n = 10): 5.4 mm (5.2–5.7); LT/BB = 1.90; LTg/BTg = 2.16; LW/BW = 1.15; BV/LV = 2.00; LF/BF = 0.82.

HEAD ( Fig. 1A–E ). Vertex medium brown, often paler on posterior angles, and with obsolete median carina yellowish brown; 2.0 × as broad as long in midline, weakly constricted in middle; disc moderately concave; anterior margin slightly, angularly projecting anteriad; posterior margin rather deeply concave; all margins elevated. Frons brown densely covered in small yellowish mottling, with more or less distinct transverse yellowish marking in middle, and with row of yellowish tubercles along margins; convex, smooth with complete median carina, peridiscal carina obsolete, not distinct. Genae yellowish brown, distinctly paler than vertex and frons, with slightly darker area above ocellus; anteroventral angle not projecting anteriad. Clypeus triangular, convex, smooth with distinct meadian carina; anteclypeus yellowish brown with apical portion darker; postclypeus blackish brown. Labium yellowish brown with last segment longer than broad, slightly shorter than penultimate. Antennae with scape short, ring-shaped, dark brown, and pedicel bulbous, brown.

THORAX ( Fig. 1A, C–E ). Pronotum brown (generally darker than vertex and mesonotum) with weak paler, yellowish median line; subtriangular, projecting anteriorly; smooth with anterior margin carinate and some yellowish tubercles in lateral fields, and pair of impressed points on each side of midline; lateral fields very narrow behind eyes; paranotal lobes brown, pale yellowish under eye and with strong black marking along ventral margin, sometimes with small yellowish tubercles, posteroventral angle rounded. Mesonotum brown, often with carinae marked with paler colour, smooth, weakly convex with shallow depression before scutellum; sublateral (peridiscal) carinae incomplete but rather distinct, some pale tubercles in angles. Tegulae brown.

TEGMINA ( Figs 1A–D , 2A–B ). Brown with veins usually slightly paler, main veins more elevated than cross-veins; distinctly convex, and about 2.2 × as long as wide, with distinct lateral hump including vein ScP+RA slightly before basal ¼; distinct, brown epipleuron; clavus closed, reaching 4 / 5 of tegmen length. Venation: as in genus description.

HIND WINGS ( Fig. 1F ). Blackish brown; veins darker than background, generally black, sometimes marked with red; well developed, with three distinct lobes ( Sarimini type) more or less equal in width; indentation between ScP-R-MP-Cu and Pcu-A1 lobes rather deep. Venation: as in genus description.

LEGS ( Figs 1A–E , 2C–D ). Generally yellowish brown, paler than tegmina; darker rings on pro- and mesofemora (basal and anteapical), about midlength of pro- and mesotibiae, and anteapical on metafemora; pro- and mesotibiae blackish apically; all spines of posterior legs black apically. Anterior and median legs slightly flattened dorsoventrally, tibiae more slender than corresponding femora; posteroventral margin of pro- and mesofemora with row of minute teeth; pro- and mesotarsi yellowish brown, rather elongate. Metatibiae with two lateral spines in distal half and six apical spines. Metatarsi yellowish brown, moderately short with first segment about as long as combined length of remaining segments. First metatarsomere with two latero-apical and six intermediate spines arranged in arc. Metatibiotarsal formula: (2) 6/ 8/ 2.

ABDOMEN ( Fig. 1B ). Brown, each segment with middle area and two spots along base darker.

MALE TERMINALIA ( Figs 3–4 ). Pygofer (Py – Fig. 3A–D ) short, about 2.4 × as high as long at midheight in lateral view, with posterior margin broadly rounded in lateral view; in caudal view suboval, 1.4 × as high as wide; dorsally abruptly, deeply notched. Gonostyli (G – Fig. 3A–D ) massive, moderately convex, subtriangular in lateral aspect with posterior margin rounded but not forming a distinct lobe, anterodorsal margins distinctly convex and posterodorsal margin slightly sinuate; capitulum (ca – Fig. 3A–B, D ) elongate, rather strongly projecting dorsad and with poorly distinct neck, curved anterodorsad and more or less evenly tapering towards apex in lateral view, with basilateral laminate process directed lateroventrad in caudal view, and with distal portion anteroposteriorly laminate, apically rounded in caudal view. Anal tube (An – Fig. 3A–D ) strongly elongate, dorsoventrally flattened, and oblong, moderately narrow with lateral margins weakly sinuate in dorsal view, about 3.4 × as long as wide in dorsal view and with anal opening in basal ¼; in lateral view, downcurved and sinuate. Aedeagus (ae – Figs 3E–L , 4 ) symmetrical, rather strongly curved posterodorsad in lateral view around distal 2 /5. Ventral lobe of periandrium (vl – Figs 3G–L , 4A–D ) laminate, spatulate, with apical margin roundly notched. Dorsal lobe of periandrium (dl – Figs 3E–G, J–K , 4A–D ) laminate, elongate, spatulate; curved in lateral view in distal portion. Laterodorsal processes of periandrium (ldp – Figs 3E–L , 4A–D ) arising lateroventrally from middle portion of dorsal lobe, curved posterodorsad and somewhat twisted, with apical hook directed dorsad moderately upcurved; elongate shaft (sp – Figs 3E–L , 4A–D ) directed cephalad, upcurved and reaching nearly to base of aedeagus, pointed apically. Aedeagus (sensu stricto, ae – Figs 3E–L , 4E–G ) surpassing dorsal and ventral lobes of periandrium, bifid with lateral margins sinuate, forming a lateral lobe distally in dorsal aspect, and with distal portion dilated in lateral view; pair of elongate, sinuate lateroventral processes (lvp – Figs 3E, G, J–L , 4E–G ), ribbon-like, arising at about distal third of aedeagus, somewhat spiralate, distally curved mesad above dorsal lobe of periandrium and reaching to about basal third of aedeagus. Connective (co – Fig. 3G ) well developed, corpus connective long, slightly curved in lateral view, tectiductus (te – Fig. 3G ) well developed, conical with anteroventral apodemes and wide anterior foramen.

Biology

Keosarima armillata Constant gen. et sp. nov. was collected in November, on lower vegetation and bushes, in moist evergreen tropical forest at about 300 m a.s.l. ( Fig. 5D ) in the Keo Seima Wildlife Sanctuary. A specimen was observed at day time, in a trophobiotic interaction with ants that were collecting the honeydew produced by the planthopper. The ants belong to an unidentified species of the genus Camponotus Mayr, 1861 ( Hymenoptera : Formicidae : Formicinae ) ( Fig. 5A–C ); the behaviour of the ants included antennal, palps and prolegs contact/ palpation which are regarded as a way to stimulate honeydew production by the planthopper (Bourgoin et al. 2023). The latter observation was previously reported in Bourgoin et al. (2023: 57, fig. 21c) under “ Sarimini indet.”.

Distribution

Cambodia: Mondulkiri Province, Keo Seima Wildlife Sanctuary ( Fig. 6 ).

Figures

Fig. 1. Keosarima armillata Constant gen. et sp. nov., dissected holotype, ♂ (RBINS). A. Habitus, dorsal view. B. Habitus, ventral view. C. Habitus, lateral view. D. Habitus, anterolateral view. E. Habitus, perpendicular view of frons. F. Right hind wing.

Fig. 2. Keosarima armillata Constant gen. et sp. nov., holotype, ♂ (RBINS). A. Right tegmen, laterodorsal view. B. Right tegmen, ventral view. C. Metatibia and metatarsus, ventral view. D. Apex of metatibia and metatarsus, ventral view. Abbreviations: see Bourgoin et al. (2015).

Fig. 3. Keosarima armillata Constant gen. et sp. nov., holotype, ♂ (RBINS), terminalia. A–D. Pygofer, anal tube and gonostyli. A. Left lateral view. B. Caudal view. C. Dorsal view. D. Posterolateral view. E–L. Aedeagus. E. Dorsal view. F. Anterodorsal view. G. Left lateral view. H. Ventral view. I. Posteroventral view. J. Left laterodorsal view. K. Left lateroventral view. L. Posterolateral view. Abbreviations: see Material and methods.

Fig. 4. Keosarima armillata Constant gen. et sp. nov., holotype, ♂ (RBINS). A–D. Periandrium. A. Dorsal view. B. Posteroventral view. C. Left lateral view. D. Posterolateral view. E–G. Aedeagus sensu stricto. E. Dorsal view. F. Posteroventral view. G. Left lateral view. Abbreviations: see Material and methods.

Fig. 5. Keosarima armillata Constant gen. et sp. nov. A–C. Specimen in trophobiotic interaction with ants (Camponotus sp.), 19 Nov. 2018. D. Habitat in Keo Seima Wildlife Sanctuary, 17 Nov. 2018.

Fig. 6. Distribution map of the species of Keosarima Constant gen. nov.