Retirima, 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 : 97-99

Genus Retirima gen. nov.

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Type species

Retirima angulata gen. et sp. nov., by present designation.

Diagnosis

The genus Retirima gen. nov. can be differentiated from all other genera of Sarimini by the following combination of characters: (1) the vertex about 1.7 × as wide as long in dorsal view; (2) the frons with complete median carina, extending down to basal portion of clypeus where it broadens into a short median hump, and peridiscal carinae nearly complete but not reaching ventral margin; (3) the tegmina elongate, about 2.2 × as long as wide, with weak lateral hump around basal ¼, not hiding costal margin in dorsal aspect, with dense network of distinctly paler cross-veins, and with distinct but narrow epipleuron; (4) the vein ScP of the tegmen long, weakly curved and reaching margin of tegmen around distal 1 /5 of tegmen length; (5) the first fork of MP and the first fork of CuA at about the same level, slightly beyond 2 /5 of the length of tegmen; (6) the anal tube elongate and rather wide, dorsoventrally flattened, oboval / subrectangular, apically truncate in dorsal view; (7) the rather massive gonostyli with anterodorsal margin generally oblique, with capitulum elongate, strongly projecting anterodorsad and with poorly distinct neck, digitiform in lateral view, and broadly falcate in caudal view; (8) the periandrium with a pair of strong laterodorsal processes arising in proximal portion of dorsal lobe, and apex of dorsal lobe distinctly acuminate; (9) the aedeagus with a pair of elongate, curved, lateroventral processes without posterior hook, arising at about ⅔ of aedeagus length.

Differential diagnosis

The most similar genera are Caimocus gen. nov., Duplexissus Wang, Zhang & Bourgoin, 2019 , Eusarima Yang, 1994 , Jagannata Distant, 1906 , Lobosarima gen. nov. and Parasarima Yang, 1994 . However, Retirima gen. nov. can be separated from all of these genera by the tegmina with dense network of pale cross-veins, the periandrium with a pair of strong laterodorsal processes arising in proximal portion of the dorsal lobe, and the apex of the dorsal lobe distinctly acuminate.

Additionally, Retirima gen. nov. can be separated (1) from Caimocus gen. nov. (see Figs 13–22) by the subrectangular anal tube in dorsal aspect (anal tube widening towards rounded apex in Caimocus ), the capitulum of the gonostyli anteroposteriorly compressed and falcate (digitiform and tapering towards the apex in Caimocus ), and the lateroventral processes of the aedaegus without posterior hook (posterior hook present in Caimocus ); (2) from Duplexissus (see illustrations in Wang et al. 2019: figs 12–22) by weakly developed hump of the tegmina (strongly developed in Duplexissus ), the generally oblique anterodorsal margin of the gonostyli (distinctly rounded in Duplexissus ) and the dorsal lobe of the periandrium without apical elongate process directed cephalad (process present on dorsal lobe of periandrium of Duplexissus ); (3) from Eusarima (see illustrations in Chan & Yang 1994: fig. 45) by the generally oblique anterodorsal margin of the gonostyli (distinctly rounded in Eusarima ), the subrectangular anal tube in dorsal aspect (elongate and tapering towards apex in Eusarima ) and the lack of dorsal spinose processes in the apical portion of the dorsal lobe of the periandrium (present in Eusarima ); (4) from Jagannata (see illustrations in Distant 1906: figs 171) by the transverse vertex, much wider than long in midline, and with anterior margin more or less truncate (vertex slightly longer than wide, and angularly produced anteriorly in Jagannata ); (5) from Lobosarima gen. nov. (see Figs 37–40) by the lack of a pair of lobes on the basidorsal portion of the periandrium (lobes present in Lobosarima ), and the lack of a ventral tooth on the lateral margin of the dorsal lobe of the periandrium (tooth present in Lobosarima ); (6) from Parasarima (see illustrations in Chan & Yang 1994: fig. 39) by the complete carina of the frons, reaching slightly beyond frontoclypeal suture (carina visible only in dorsal half of the frons in Parasarima ), and by the posterior portion of the gonostyli forming a distinct rounded lobe (gonostyli without posterior lobe in Parasarima ).

Etymology

The genus name is the combination of ‘ reticulatus ’ (Latin), meaning ‘reticulate’, and ‘ Sarima ’, the name of the type genus of the tribe Sarimini . It refers to the reticulate aspect of the tegmina, with numerous cross veins. Gender feminine.

Description

Medium sized (around 6.0 mm), very convex, moderately elongate, rather robust-bodied.

COLOUR. Mostly brown with cross-veins of tegmina forming distinctly paler network.

HEAD. Vertex distinctly broader than long in midline (about 1.7 ×), weakly concave with weak median carina; anterior margin forming a widely obtuse angle, posterior one rather deeply concave; all margins carinate. Frons 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, and peridiscal carinae nearly complete but not reaching ventral margin; obsolete tubercles between peridiscal carina and lateral margin; maximum breadth slightly under level of antennae; dorsal margin nearly straight (angles weakly elevated). Anteroventral angle of genae slightly projecting anteriad. Ocelli present, under eye. Clypeus triangular, convex, smooth, not keeled or carinate. Labium with last segment longer than broad, shorter than penultimate. Antennae with scape short, ring-shaped, and bulbous pedicel.

THORAX. Pronotum 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 tubercles, very narrow behind eyes; paranotal lobes with tubercles along external margin, and with posteroventral angle rounded. Mesonotum subtriangular with posterolateral margins slightly incurved and weakly carinate, smooth, weakly convex with distinct median and sublateral carinae; shallow depression before scutellum.

TEGMINA. Distinctly convex, elongate, about 2.2 × as long as wide, with longitudinal veins elevated; 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; distinct but narrow epipleuron; clavus closed, reaching about 4 /5 of tegmen length. Venation: ScP+R rather short; ScP+RA long, reaching external margin of tegmen around distal 1 /5 of tegmen length; RP unforked, long and weakly curved; first fork of MP slightly after 2 /5 of tegmen length, MP1 with two or three terminales; first fork of CuA slightly more distal to MP fork; Pcu and A1 fused slightly beyond halflength of clavus, Pcu+A1 reaching apex of clavus; cross-veins numerous.

HIND WINGS. Well developed, with three distinct lobes ( Sarimini type) more or less equal in width; mostly blackish brown. Venation: ScP+R and CuA furcate; MP simple, sinuate; second branch of CuA fused distally with CuP; Pcu and A1 fused on basal half, Pcu unforked and A2 simple; one transverse vein between second branch of ScP+R and MP, and between MP and first branch of CuA.

LEGS. 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; 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. Pygofer short, about 2.3 × as high as long at midheight in lateral view, with posterior margin forming distinct, evenly rounded lobe in lateral view; in caudal view suboval, about 1.3 × as high as wide. Gonostyli rather massive, distinctly convex, with anterodorsal margin generally oblique, with capitulum elongate, strongly projecting anterodorsad and with poorly distinct neck, digitiform and curved in lateral view, and broadly falcate in caudal view, with distinct lateral tooth. Anal tube elongate and rather wide, dorsoventrally flattened, oboval / subrectangular, apically truncate in dorsal view, with anal opening around basal ⅓; in lateral view, more or less straight. Aedeagus symmetrical, distinctly curved posterodorsad in lateral view. Ventral lobe of periandrium rather long, laminate and spatulate. Dorsal lobe of periandrium with apex distinctly acuminate and with a pair of strong laterodorsal processes arising in proximal portion. Aedeagus (sensu stricto) slightly surpassing dorsal and ventral lobes of periandrium, bifid on most length, with a pair of elongate, curved, lateroventral processes without posterior hook, arising at about ⅔ of aedeagus length. Connective well developed, corpus connective long, straight in lateral view, tectiductus well developed, conical with anteroventral apodemes and rather wide anterior foramen.

Distribution

Vietnam: Thừa Thiên-Huế Province.

Species included

Retirima angulata gen. et sp. nov.