Varisphaerius, Constant & Pham, 2025

Constant, Jérôme & Pham, Hong Thai, 2025, Issid planthoppers from Bach Ma and Phong Dien in Central Vietnam: (II) Tribe Hemisphaeriini (Hemiptera: Fulgoromorpha: Issidae), European Journal of Taxonomy 994 (1), pp. 1-76 : 62-64

Genus Varisphaerius gen. nov.

urn:lsid:zoobank.org:act:AA5E3911-84F5-40AA-AF7D-8517BEBE6178

Type species

Varisphaerius hoaiae sp. nov., by present designation.

Diagnosis

Varisphaerius gen. nov. can be differentiated from all other genera of Hemisphaeriini by the following combination of characters:

(1) the hind wings unilobous, rather elongate and rudimentary;

(2) the strongly rounded costal margin of the tegmina (in dorsal view) and very convex body making the insect strongly hemispherical;

(3) the frons much longer than wide, smooth, without carina;

(4) the clypeus distinctly keeled in midline but not projecting cephaloventrad;

(5) the pro- and mesofemora without contrasting transverse black lines or rings;

(6) the pygofer without spine on posterior margin;

(7) the asymmetrical aedeagus with a basal lateral laminate process on each side of the periandrium; (8) the pair of well developed, elongate lateroventral processes of the aedeagus.

Differential diagnosis

The most similar genera are Ceratogergithus Gnezdilov, 2018 , Gergithus Stål, 1870 , Hemisphaerius Schaum, 1850 , Ishiharanus Hori, 1969 , Maculergithus Constant & Pham, 2016 and Melichergithus Constant & Pham, 2024. However, Varisphaerius can be separated from all of these genera, except for Hemisphaerius , by its reduced hind wings. The character of possessing reduced hind wings is shared with Hemisphaerius , but Varisphaerius shows a much more elongate frons (1.4 times as long as wide vs 0.9–1.1 times in Hemisphaerius ), a keeled clypeus (not keeled in Hemisphaerius ), as well as a well developed pair of lateroventral processes of the aedeagus and a basal lateral laminate process on each side of the periandrium (all absent in Hemisphaerius ).

Additionally, Varisphaerius gen. nov. can be separated:

(1) from Ceratogergithus by the absence of a spine on the posterior margin of the pygofer (always present in species of Ceratogergithus ), by the strongly elongate frons (frons wider than long in Ceratogergithus ), by the keeled clypeus (not keeled in Ceratogergithus ) and by the lateral laminate processes of the periandrium (absent in Ceratogergithus );

(2) from Gergithus Stål, 1870 by the clypeus being keeled but not strongly projecting anteroventrally;

(3) from Ishiharanus by having a keeled clypeus (not keeled in Ishiharanus ) and by the lateral laminate processes of the periandrium (absent in Ishiharanus );

(4) from Maculergithus by the strongly elongate frons (frons wider than long in Maculergithus ) and by having a keeled clypeus (not keeled in Maculergithus );

(5) from Melichergithus by the strongly elongate frons (frons wider than long in Melichergithus) and by having a keeled clypeus (not keeled in Melichergithus).

Etymology

The genus name is formed from the combination of ‘ varius ’ (adj., Latin) meaning ‘diverse, various, variegated, varied’ and ‘ Hemisphaerius ’, the name of the type genus of the tribe Hemisphaeriini . It refers to the striking and highly variable colouration of the type species, and to the character of possessing reduced hind wings, shared with Hemisphaerius .

Description

Rather large (5.0– 6.6 mm), very convex, round-bodied Hemisphaeriini .

COLOUR. Very variable combinations of chocolate brown to black, bright (golden) yellow and white.

HEAD. Vertex broader than long in midline, weakly concave; anterior margin weakly curved, posterior one concave. Frons weakly convex, distinctly longer in midline than wide, smooth; maximum width slightly under level of antennae. Clypeus convex, smooth, medially keeled. Labium with last segment longer than broad, shorter than penultimate one. Antennae with scape short, ring-shaped, and bulbous pedicel.

THORAX. Pronotum wider than head, short, about ¼ length of mesonotum in midline; disc concave; paranotal lobes with angularly rounded lateroventral angle. Mesonotum subtriangular with postrolateral margins slightly incurved, smooth with weak transverse carina parallel to anterior margin; without longitudinal carinae.

TEGMINA. Strongly convex, with rounded lateral margins in dorsal view (making the insect look hemispherical); about as wide as long when taken together in dorsal view; apical margin rounded; venation weakly distinct, with longitudinal veins marked as weak, blunt ridges.

HIND WINGS. Strongly reduced and shorter than tegmina, rather elongate, unilobed. Venation reticulate with main longitudinal veins distinct basally (C, ScP+R, MP, CuA) and numerous cross-veinlets in distal portion. Costal margin slightly sinuate; sutural margin sinuate, rounded after midlength and apical margin rounded.

LEGS. Distinctly elongate and slender, with pro- and mesofemora dorsoventrally flattened; pro- and mesotibiae slender with mesotibiae slightly shorter and wider; pro- and mesotarsi rather elongate; metatibiae with 2 lateral spines in distal half and 6 apical spines. Metatarsi rather short with first segment shorter than combined length of remaining segments. Metatibiotarsal formula: (2)6 /12 / 2.

MALE TERMINALIA. Pygofer short, about 2.2 times as high as long at midheight in lateral view, with posterior margin angularly rounded in lateral view. Gonostyli convex, with posterior margin roundly projecting caudad in lateral view; capitulum rather elongate, with a wide neck with posterior margin sinuate, with apical tooth directed mesad and lateral laminate process in distal portion. Anal tube dorsoventrally flattened, rather wide in dorsal view and with anal opening in basal half. Aedeagus asymmetrical, strongly curved posterodorsad in lateral view. Ventral lobe of periandrium laminate and gently twisted to the right; lateral lobes of periandrium laminate, rounded, partly covering elongate lateroventral processes of aedeagus. Connective well developed, corpus connective long, regularly curved in lateral view, tectiductus well developed, conical with anteroventral apodemes and wide anterior foramen.

Distribution

Vietnam: Thừa Thiên-Huế Province.

Species included

Varisphaerius hoaiae sp. nov.