Caimocus sinuatus, 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 : 42-48

Caimocus sinuatus gen. et sp. nov.

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Figs 20–22

Diagnosis

Caimocus sinuatus gen. et sp. nov. can be recognized by the elongate lateroventral processes of the aedeagus distinctly sinuate in distal portion ( lvp – Figs 21G–L, 22E–G).

Differential diagnosis

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

Etymology

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

Type material

Holotype

VIETNAM • ♂; Th ừa Thiên-Huế Province , Bach Ma National Park, road to Bach Ma Peak; 16°11′45.73″ N, 107°51′46.34″ E; 1325 m a.s.l.; 14 Sep. 2024; H. T. T Nguyen leg.; [by] net; AU0696; VNMN.

Paratype

VIETNAM – Th ừa Thiên-Huế Province • 1 ♂; 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; I.G.: 34.640; RBINS .

Description

MEASUREMENTS AND RATIOS. LT: ♂ (n = 1): 5.5 mm; LT/ BB = 2.14; LTg/BTg = 2.45; LW/BW = 1.23; BV/ LV = 1.96; LF/BF = 0.91.

HEAD ( Fig. 20A–E). Vertex brown, slightly paler laterally in posterior portion, with weak median carina yellowish; 1.9 × as broad as long in midline, slightly constricted in middle; disc weakly concave; anterior margin more or less 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 brown with anteroventral angle slightly projecting anteriad. Clypeus triangular, convex, smooth, not keeled or carinate; anteclypeus dark brown with base 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. 20A, C–E). Pronotum brown, darker than vertex and mesonotum, with paler, yellowish median carina and yellowish tubercles 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 blackish brown, pale yellowish along ventral margin and with yellowish tubercles along external margin; posteroventral angle rounded. Mesonotum brown, with carinae and some tubercles in lateral angles paler; smooth, weakly convex with shallow depression before yellowish scutellum; median carina distinct, sublateral (peridiscal) carinae distinct. Tegulae brown.

TEGMINA ( Fig. 20A–D). Brown with paler poorly defined median band and apical portion; main veins more or less concolourous, elevated, and 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. 20F). 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. 20A–E). Seen from above, yellowish brown, paler than tegmina; apex of pro- and mesotibiae (narrowly), pro- and mesofemora, most surface of metafemora and basal portion of metatibiae dark brown; pro- and mesofemora with anteapical portion paler, yellowish; 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. 20B). Yellowish brown with median area and a spot along basal margin of segments on each side, dark brown.

MALE TERMINALIA ( Figs 21–22). Pygofer ( Py – Fig. 21A–D) short, about 2.1 × as high as long at midheight in lateral view, with posterior margin broadly rounded in lateral view; in caudal view suboval, 1.3 × as high as wide; dorsally deeply notched. Gonostyli ( G – Fig. 21A–D) relatively massive, moderately convex, with anterodorsal margin weakly concave, then distinctly 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. 21A–C) elongate, digitiform, strongly projecting dorsad and with rather long neck, curved anterodorsad and evenly tapering towards anteriorly pointed apex in lateral view, in caudal view sinuate, flattened antero-posteriorly, and with basilateral tooth curved lateroventrad. Anal tube ( An – Fig. 21A–D) rather elongate, dorsoventrally flattened, oboval, evenly widening from base towards rounded apical margin in dorsal view, about 2.0 × as long as wide in dorsal view, anal opening in basal ⅓; in lateral view abruptly narrowing at anal opening, then weakly downcurved. Aedeagus ( ae – Figs 21E–L, 22) symmetrical, curved posterodorsad in lateral view. Ventral lobe of periandrium ( vl – Figs 21F–L, 22A–D) laminate, spatulate with apical margin round, slightly shorter than dorsal lobe and aedeagus sensu stricto; in basal portion, distinct, moderately rounded lateral lamina ( lvl – Fig. 22B, D) conceiling (combined with dorsal lobe) middle portion of lateroventral processes of aedeagus. Dorsal lobe of periandrium ( dl – Figs 21E–I, K–L, 16A– D) in proximal ⅔, moderately expanded into lamina lateroventrally, with sides evenly tapering in distal portion towards rounded apex, lamina partly covering lateroventral processes of aedeagus; laterodorsal processes of periandrium ( ldp – Figs 21E–F, H–L, 22A, C–D) arising ventrally from basal portion of dorsal lobe, shaft-shaped, curved posterodorsad and sinuate in distal portion in lateral view, pointed and slightly curved mesad apically. Aedeagus (sensu stricto, ae – Figs 21E, H, J–L, 22E–H) slightly shorter than laterodorsal processes of periandrium, bifid, each shaft more or less parallel-sided to rounded apex; lateroventral processes ( lvp – Figs 21E, G–L, 22E–H) arising in distal ⅓, directed cephalad, generally robust and elongate (rather slender) and moderately, evenly curved mesad to sinuate distal portion in ventral view, weakly curved to more distinctly upcurved distal portion in lateral view, inflated at base and with posterior distinct, moderately developed hook curved posterodorsad.

Remark

Connective ( co – Fig. 21H) and tectiductus ( te – Fig. 21H) not well developed in the examined specimen, regarded as somewhat teneral.

Biology

Caimocus sinuatus gen. et sp. nov. was collected in May and September 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. 22I).