Retirima angulata, 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 : 99-105

Retirima angulata gen. et sp. nov.

urn:lsid:zoobank.org:act:

Figs 49–52

Diagnosis

Retirima angulata gen. et sp. nov. is the only species in the genus Retirima gen. nov. The characters of the male terminalia are probably relevant diagnostic features to recognize the species, e.g., the subrectangular anal tube in dorsal view, the shape of the gonostyli, including the capitulum in lateral and caudal view and, the shape of the dorsal and ventral lobes of the periandrium, the size and shape (curvature) of the lateroventral processes of the aedeagus ( Figs 51, 52A–J).

Differential diagnosis

The most similar species belong to the genera Caimocus gen. nov., Duplexissus Wang, Zhang & Bourgoin, 2019 , Eusarima Yang, 1994 , Jagannata Distant, 1906 , Lobosarima gen. nov. and Parasarima Yang, 1994 , which can be separated by the characters given for the genus Retirima gen. nov.

Etymology

The species epithet ‘ angulatus ’ is a Latin adjective meaning ‘angular’, and it refers to the shape of the lateroventral processes of the aedeagus.

Type material

Holotype

VIETNAM • 1 ♂; Th ừa Thiên-Huế Province, Bach Ma National Park, [ 16°11′45″ N, 107°50′51″ E]; 1158 m a.s.l.; 27 May 2023; T. T. H. Nguyen leg.; Rhodo [dendron] trail; VNMN.

Paratypes

VIETNAM – Thiên-Huế Province • 1 ♂; same data as for holotype; VNMN • 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 • 1 ♀; Bach Ma National Park ; 16°12′ N, 107°52′E; 15–16 Jul. 2011; J. Constant and J. Bresseel leg.; summit, day [time] collecting; I.G.: 31.933; RBINS .

Description

MEASUREMENTS AND RATIOS. LT: ♂ (n = 1): 6.0 mm; LT/BB = 1.85; LTg/BTg = 2.23; LW/BW = 1.23; BV/ LV = 1.69; LF/BF = 0.93.

HEAD ( Fig. 49A–E). Vertex brown, paler in posterior angles, median line, and along margins; 1.7 × as wide as long in midline, weakly concave with weak median carina; anterior margin forming widely obtuse angle, posterior one rather deeply concave; all margins carinate. Frons yellowish brown with dense yellow pitting, slightly paler in ventral portion, moderately convex, narrowly visible from above, nearly 1.1 × as wide as long in midline, somewhat rugulose with distinct complete median carina extending down to basal portion of clypeus where it broadens into short median hump; peridiscal carina nearly complete but not reaching frontoclypeal suture; yellowish obsolete tubercles between peridiscal carina and lateral margin; maximum breadth slightly under level of antennae; dorsal margin nearly straight with angles weakly elevated. Genae yellow, washed with brown around anteroventral angle; anteroventral angle slightly projecting anteriad. Ocelli present, under eye. Clypeus yellowish brown (slightly paler than frons), darker towards apex; triangular, convex, smooth (without pitting), not keeled or carinate. Labium with last segment longer than broad, shorter than penultimate. Antennae with scape yellowish brown, short, ring-shaped, and pedicel bulbous, black with postero-apical yellowish marking.

THORAX ( Fig. 49A, C–E). Pronotum dark brown with more or less distinct transverse yellowish band in middle; subtriangular, projecting anteriorly in blunt right angle, about 0.63 × as long in midline, as mesonotum; smooth with anterior margin carinate and pair of impressed points on each side of paler obsolete median carina; lateral fields with yellowish tubercles, very narrow behind eyes; paranotal lobes yellowish brown with darker marking behind eye, and yellowish tubercles along external margin; posteroventral angle rounded. Mesonotum brown, somewhat darker in lateral angles, and with paler scutellum; subtriangular with posterolateral margins slightly incurved and weakly carinate, smooth, weakly convex with distinct median and sublateral carinae; shallow depression before scutellum.

TEGMINA ( Figs 49A–D, 50A–B). Rather dark brown with main veins slightly paler and elevated; costal margin on most length and dense network of cross-veins pale yellowish; distinct but narrow epipleuron; distinctly convex, elongate, about 2.2 × as long as wide,; costal margin evenly rounded; apical margin rounded; distinct but weak lateral hump including vein ScP+RA around basal ¼, not hiding costal margin in dorsal aspect; costal margin hidden by vein RP in distal 0.3, in dorsal view; clavus closed, reaching about 4 / 5 of tegmen length. Venation as in genus description.

HIND WINGS ( Fig. 49F). Blackish brown with paler area basally between ScP+R and CuA and along margin of A2 lobe; well developed, with three distinct lobes ( Sarimini type) more or less equal in width. Venation as in genus description.

LEGS ( Figs 49A–E, 50C–D). Yellowish brown with narrow apical marking on pro- and mesotibiae, ventral line on metafemora and all onychiums, dark brown; all spines of hind legs black apically; moderately elongate, slender, with pro- and mesofemora and pro- and mesotibiae slightly flattened dorsoventrally, tibiae more slender than corresponding femora; posteroventral margin of pro- and mesofemora with row of minute teeth (slightly darker); 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 seven intermediate spines arranged in arc. Metatibiotarsal formula: (2) 6 /9 / 2.

MALE TERMINALIA ( Figs 51–52). Pygofer ( Py – Fig. 51A–D) short, about 2.3 × as high as long at midheight in lateral view, with posterior margin forming distinct, evenly rounded lobe, and anterior margin incurved in lateral view; in caudal view suboval, about 1.3 × as high as wide, widest in ventral portion. Gonostyli ( G – Fig. 51A–D) rather massive, distinctly convex, with anterodorsal margin weakly rounded, generally oblique, with capitulum elongate, strongly projecting anterodorsad and with poorly distinct neck, digitiform, narrow and curved in lateral view, and broadly falcate with rounded apex in caudal view, with distinct lateral tooth curved lateroventrad. Anal tube ( An – Fig. 51A–D) elongate and rather wide, about 2.3 × as long in midline, as wide; dorsoventrally flattened, oboval with sides subparallel, basally widening to anal opening around basal ⅓ and apically truncate (margin slightly incurved) in dorsal view; in lateral view, more or less straight, weakly sinuate. Aedeagus ( ae – Fig. 51E– L) symmetrical, distinctly, evenly curved posterodorsad in lateral view. Ventral lobe of periandrium ( vl – Figs 51 GL, 52A–F) rather long, wide in basal portion then tapering to about midlength, further widening, laminate and spatulate in distal portion with apical margin rounded. Dorsal lobe of periandrium ( dl – Figs 51E–F, H–K, 52A–B, E–F) with apex distinctly acuminate and with a pair of strong, elongate, apically pointed laterodorsal processes of periandrium ( ldp – Figs 51H–L, 52A–F) arising in proximal portion and directed posterodorsad. Aedeagus (sensu stricto ae – Figs 51E–F, H–L, 52G–J) slightly surpassing dorsal and ventral lobes of periandrium, bifid on most length, with lateral margin roundly tapering towards somewhat mucronate apex; dorsally, inner margin slightly elevated in distal portion; pair of elongate, apically pointed lateroventral processes ( lvp – Figs 51G–L, 52G–J) without posterior hook, arising at about ⅔ of aedeagus length and directed cephaloventrad, sinuate to abrupt right angle, resulting in distal half of processes transverse and more or less touching each other. Connective ( co – Fig. 51H) well developed, corpus connective long, straight in lateral view, tectiductus ( te – Fig. 51H) well developed, conical with anteroventral apodemes and rather wide anterior foramen.

Biology

Retirima angulata gen. et sp. nov. was collected in the months of May and July at altitudes between 1150 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/habitat ( Constant & Pham 2025a: fig. 2a): “summit” ( Constant & Pham 2025a: figs 2a(5), 4b).

Distribution

Vietnam: Thừa Thiên-Huế Province, Bach Ma National Park ( Fig. 52K).