Caimocus robustus, Constant & Pham, 2025

Constant, Jérôme & Pham, Hong Thai, 2025, Issid planthoppers from Bach Ma and Phong Dien in Central Vietnam. (III) Tribe Sarimini (Hemiptera: Fulgoromorpha: Issidae), European Journal of Taxonomy 1025, pp. 1-109 : 37-42

Caimocus robustus gen. et sp. nov.

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Figs 17–19

Diagnosis

Caimocus robustus gen. et sp. nov. can be recognized by the robust and strongly curved mesad lateroventral processes of the aedeagus ( lvp – Figs 18G–L, 19E–G).

Differential diagnosis

The new species is close to Caimocus elephas gen. et sp. nov. and Caimocus sinuatus gen. et sp. nov. but it can be separated from both other species by the shape of the lateroventral processes of the aedeagus ( lvp – Fig. 19E–G) robust and strongly curved mesad while they are elongate (rather slender) and moderately, evenly curved in C. elephas ( lvp – Fig. 16D–F), and distinctly sinuate in distal portion in C. sinuatus ( lvp – Fig. 22E–H).

Etymology

The species epithet ‘ robustus ’ is a Latin adjective meaning ‘robust’. It refers to the robust shape of the lateroventral processes of the aedeagus.

Type material

Holotype

VIETNAM • ♂; Th ừa Thiên-Huế Province, Bach Ma National Park; 16°11′18″ N, 107°50′56″ E; 1300– 1400 m a.s.l.; 11–21 May 2023; J. Constant and L. Semeraro leg.; summit; VNMN.

Paratypes

VIETNAM – Th ừa Thiên-Huế Province • 1 ♂; same data as for holotype; VNMN • 3 ♂♂; same data as for holotype; I.G.: 34.640; RBINS .

Description

MEASUREMENTS AND RATIOS. LT: ♂ (n = 5): 5.7 mm (5.6–5.7); LT/BB = 2.08; LTg/BTg = 2.40; LW/BW = 1.25; BV/LV = 2.14; LF/BF = 0.84.

HEAD ( Fig. 17A–E). Vertex pale brown, darker in anterior portion, with yellowish weak median carina; 2.1 × as broad as long in midline, slightly constricted in middle; disc weakly concave; anterior margin angularly projecting anteriad (widely obtuse angle); posterior margin rather deeply concave; all margins moderately carinate. Frons variegated brown, with paler transverse area in middle; distinctly darker dorsally, between peridiscal carina and dorsal margin; weakly convex, smooth with distinct, complete median carina; peridiscal carina distinct mostly in dorsal portion of frons; some yellowish tubercles along lateral margins. Genae yellowish with anteroventral angle slightly projecting anteriad. Clypeus triangular, convex, smooth, not keeled or carinate; anteclypeus dark brown with base and (partly) sides yellowish; postclypeus black brown. Labium yellow-brown with last segment longer than broad, shorter than penultimate. Antennae with scape short, ring-shaped, yellowish brown, and pedicel bulbous, dark brown.

THORAX ( Fig. 17A, C–E). Pronotum dark brown, paler in anterior portion, generally darker than vertex, with paler, yellowish median carina and yellowish tubercles more or less in rows, in lateral fields; subtriangular, projecting anteriorly; generally smooth with anterior margin carinate and pair of impressed points on each side of midline; lateral fields very narrow behind eyes; paranotal lobes dark brown, darker with yellowish tubercles in external side portion, pale yellowish along ventral margin; posteroventral angle rounded. Mesonotum brown, often with carinae, apex of scutellum and some tubercles in lateral angles marked with yellowish, smooth, weakly convex with shallow depression before scutellum; median carina distinct, sublateral (peridiscal) carinae distinct. Tegulae yellowish brown.

TEGMINA ( Figs 17A–D). Brown with paler poorly defined median band (often largely interrupted dorsally) and apical portion; CuP paler than background, other main veins more or less concolourous, elevated; cross-veins weakly raised and generally paler than background; distinctly convex, and about 2.4 × as long as wide, with distinct lateral hump including vein ScP+RA slightly before basal ⅓; without distinct epipleuron; clavus closed, surpassing ¾ of tegmen length. Venation as in genus description.

HIND WINGS ( Fig. 17F). Blackish brown, turning slightly darker in distal portion; veins generally darker than background; well developed, with three distinct lobes ( Sarimini type) more or less equal in width; indentation between ScP-R-MP-Cu and Pcu-A1 lobes moderately deep. Venation as in genus description.

LEGS ( Fig. 17A–E). Yellowish brown, paler than tegmina; apex of pro- and mesotibiae, pro- and mesofemora, distal and external portions of metafemora and basal portion of metatibiae darker; 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 rather elongate. Metatibiae with two lateral spines in distal half, and six apical spines. Metatarsi rather 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. 17B). Pale brown on lateral portion, median area darker.

MALE TERMINALIA ( Figs 18–19). Pygofer ( Py – Fig. 18A–D) short, about 2.3 × as high as long at midheight in lateral view, with posterior margin broadly rounded in lateral view; in caudal view suboval, about 1.4 × as high as wide; dorsally deeply notched. Gonostyli ( G – Fig. 18A–D) relatively massive, moderately convex, with anterodorsal margin concave, then upcurved at base of capitulum; ventral margin rounded; posterior portion roundly projecting caudad into a posterior lobe in lateral view, forming nearly right angle at base of capitulum; capitulum ( ca – Fig. 18A–B, D) elongate, digitiform, strongly projecting dorsad and with rather long neck, curved anterodorsad and evenly tapering towards apex in lateral view, in caudal view sinuate, flattened antero-posteriorly, and with basilateral tooth directed lateroventrad. Anal tube ( An – Fig. 18A–D) moderately elongate, dorsoventrally flattened, oboval, evenly widening from base towards rounded apical margin in dorsal view, about 1.5 × as long as wide in dorsal view, anal opening in basal ⅓; in lateral view abruptly narrowing at anal opening, then more or less straight. Aedeagus ( ae – Figs 18E–L, 19) symmetrical, curved posterodorsad in lateral view. Ventral lobe of periandrium ( vl – Figs 18F–J, L, 19A–C) laminate, rather elongate, spatulate with apical margin round, slightly shorter than dorsal lobe and aedeagus sensu stricto; in basal portion, distinct, rounded lateral lamina ( lvl – Fig. 19B–D) concealing (combined with dorsal lobe) middle portion of lateroventral processes of aedeagus. Dorsal lobe of periandrium ( dl – Figs 18E–L, 19A–D) in proximal ⅔, moderately expanded into lamina lateroventrally, with sides slightly sinuate, evenly tapering in distal portion towards rounded apex, lamina partly covering lateroventral processes of aedeagus; laterodorsal processes of periandrium ( ldp – Figs 18E–K, 19A–D) arising ventrally from basal portion of dorsal lobe, shaft-shaped, curved posterodorsad, then pointed and slightly curved mesad apically. Aedeagus (sensu stricto, ae – Figs 18E–K, 19E–G) slightly shorter than laterodorsal processes of periandrium, bifid, each shaft more or less parallel-sided to rounded apex; lateroventral processes ( lvp – Figs 18E, G–L, 19E–G) arising in distal ⅓, directed cephalad, robust, elongate, distinctly curved laterad basally, then slightly curved (more or less parallel), and strongly curved mesad in distal portion, weakly curved in lateral view, pointed apically, inflated at base and with slender, elongate posterior hook curved posterodorsad. Connective ( co – Fig. 18G–K) well developed, corpus connective long, weakly curved in lateral view, tectiductus ( te – Fig. 18G–L) well developed, conical with anteroventral apodemes and wide anterior foramen.

Biology

Caimocus robustus gen. et sp. nov. was collected in May at altitudes between 1300 and 1400 m a.s.l., in moist evergreen tropical forest. The specimens were sitting on small branches and leaves, on lower vegetation, bushes and trees. In Bach Ma National Park, it was found at the following collecting site/ habitats ( Constant & Pham 2025a: fig. 2a): “summit” ( Constant & Pham 2025a: figs 2a(5), 4b).

Distribution

Vietnam: Thừa Thiên-Huế Province, Bach Ma National Park ( Fig. 19H).