Caimocus, 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 : 28-31

Genus Caimocus gen. nov.

urn:lsid:zoobank.org:act:

Type species

Caimocus elephas gen. et sp. nov., by present designation.

Diagnosis

The genus Caimocus gen. nov. can be differentiated from all other genera of Sarimini by the following combination of characters: (1) the vertex less than two × as wide as long in dorsal view; (2) the frons with complete median carina and rather weak peridiscal carinae, mostly distinct in dorsal portion of frons; (3) the tegmina elongate, about 2.3 × as long as wide, with distinct lateral hump slightly before basal ⅓ hiding costal margin in dorsal aspect, and without distinct 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, around halflength of tegmen; (6) the anal tube moderately elongate, dorsoventrally flattened, and oboval, widening from base towards apical portion in dorsal view; (7) the massive gonostyli, with capitulum elongate, strongly projecting anterodorsad and with poorly distinct neck, and with anterodorsal margin distinctly concave; (8) the aedeagus with a single pair of elongate, subapical, lateroventral processes bearing a posterior hook curved posterodorsad, and with the dorsal lobe of the periandrium expanded lateroventrally in basal portion.

Differential diagnosis

The most similar genera are Duplexissus Wang, Zhang & Bourgoin, 2019 , Eusarima Yang, 1994 , Jagannata Distant, 1906 , Lobosarima gen. nov., Parasarima Yang, 1994 and Retirima gen. nov. However, Caimocus gen. nov. can be separated from all of these genera by showing a posterior hook on the lateroventral processes of the aedeagus (absent in the other genera) and the oboval anal tube in dorsal view, widening towards the posterior (elongate and more or less parallel-sided in the other genera).

Additionally, Caimocus gen. nov. can be separated (1) from Duplexissus (see illustrations in Wang et al. 2019: figs 12–22) by the concave 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 ); (2) from Eusarima (see illustrations in Chan & Yang 1994: fig. 45) by the concave anterodorsal margin of the gonostyli (distinctly rounded in Eusarima ); (3) from Jagannata (see illustrations in Distant 1906: fig. 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 ); (4) from Lobosarima gen. nov. (see Figs 37–40) by lack of a pair of basal dorsolateral lobes of the periandrium (present in Lobosarima ), the dorsal lobe of periandrium wider than ventral lobe in proximal half (dorsal lobe narrower than ventral lobe basally in Lobosarima ), the lack of a gap between the dorsal and ventral lobes of the periandrium in lateral view (large gap in ventral portion of periandrium in Lobosarima ), the capitulum of the gonostyli digitiform and tapering towards apex (anteroposteriorly compressed, falcate in Lobosarima ); (5) from Parasarima (see illustrations in Chan & Yang 1994: fig. 39) by the complete carina of the frons, reaching 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 ); (6) from Retirima gen. nov. (see Figs 49–52) by the tegmina without dense network of pale cross-veins (present in Retirima ), the capitulum of the gonostyli digitiform and tapering towards the apex (anteroposteriorly compressed and falcate in Retirima ), and the apex of the dorsal lobe of the periandrium rounded (distinctly acuminate in Retirima ).

Etymology

The genus name is derived from ‘cái móc’, the Vietnamese word for ‘hook’, and refers to the basal hook on the lateroventral process of the aedeagus present in the species of the new genus. Gender masculine.

Description

Medium sized (around 5.4–6.0 mm), very convex, moderately elongate, rather robust-bodied.

COLOUR. Mostly brown.

HEAD. Vertex distinctly broader than long in midline (about 1.9 ×), weakly concave with weak median carina; anterior margin forming a widely obtuse angle, posterior one rather deeply concave; all margins moderately carinate. Frons weakly convex, narrowly visible from above, nearly 1.1–1.2 × as wide as long in midline, smooth with distinct complete median carina, and peridiscal carina distinct in dorsal half portion of frons; tubercles between peridiscal carina and lateral margin; maximum breadth slightly under level of antennae; dorsal margin weakly concave to nearly straight. 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 rounded 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 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, smooth, weakly convex with distinct median and sublateral carinae; shallow depression before scutellum; some tubercles on lateral angles.

TEGMINA. Distinctly convex, elongate, about 2.3–2.4 × as long as wide, with longitudinal veins elevated; costal margin broadly rounded laterad at basal 2/5; apical margin rounded; distinct lateral hump including vein ScP+RA slightly before basal ⅓, hiding costal margin in dorsal aspect; costal margin hidden by vein RP in distal 2 /5, in dorsal view; no distinct epipleuron; clavus closed, surpassing ¾ 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 before midlength of tegmen, MP1 with three terminales; first fork of CuA at about same level, around halflength of tegmen; Pcu and A1 fused slightly beyond halflength of clavus, Pcu+A1 reaching apex of clavus; cross-veins more numerous and more strongly marked along costal margin and in distal half of tegmen.

HIND WINGS. Well developed, with three distinct lobes ( Sarimini type) more or less equal in width; mostly 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 six intermediate spines arranged in arc. Metatibiotarsal formula: (2) 6/ 8/ 2.

MALE TERMINALIA. Pygofer short, about 2.0 × 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. Gonostyli rather massive, moderately convex, with posterior portion roundly projecting caudad into a posterior lobe in lateral view, and anterodorsal margin (weakly) concave; capitulum elongate, strongly projecting dorsad and with rather long neck, curved anterodorsad and more or less evenly tapering towards apex in lateral view, with lateral tooth. Anal tube moderately elongate, dorsoventrally flattened and oboval, widening from base towards apical portion in dorsal view, about 1.7 × as long as wide and with anal opening in basal ⅓; in lateral view, weakly downcurved. Aedeagus symmetrical, curved posterodorsad in lateral view. Ventral lobe of periandrium laminate, spatulate. Dorsal lobe of periandrium moderately wide, evenly tapering in distal portion towards rounded apex, and moderately expanded lateroventrally in basal portion, forming lamina; laterodorsal processes of periandrium arising ventrally from basal portion of dorsal lobe, shaft-shaped, apically pointed and curved posterodorsad. Aedeagus (sensu stricto) slightly surpassing dorsal and ventral lobes of periandrium but shorter than laterodorsal processes of periandrium, bifid in distal portion, and with robust lateroventral processes arising in distal third, curved ventrocephalad, with a posterior hook curved posterodorsad. Connective well developed, corpus connective long, slightly curved in lateral view, tectiductus well developed, conical with anteroventral apodemes and wide anterior foramen.

Distribution

Vietnam: Thừa Thiên-Huế and Quang Tri provinces.

Species included

Caimocus elephas gen. et sp. nov.

Caimocus robustus gen. et sp. nov.

Caimocus sinuatus gen. et sp. nov.