Disconius Skejo, Pushkar et Tumbrinck, 2022

Skejo, Josip, Pushkar, Taras I., Kasalo, Niko, Pavlović, Marko, Deranja, Maks, Adžić, Karmela, Tan, Ming Kai, Rebrina, Fran, Muhammad, Amira Aqilah, Abdullah, Nurul Ashikin, Japir, Razy, Chung, Arthur Y. C. & Tumbrinck, Josef, 2022, Spiky pygmy devils: revision of the genus Discotettix (Orthoptera: Tetrigidae) and synonymy of Discotettiginae with Scelimeninae, Zootaxa 5217 (1), pp. 1-64 : 52-53

Genus Disconius Skejo, Pushkar et Tumbrinck gen. n.

Type species: Discotettix shelfordi Hancock, 1907 (= Disconius shelfordi comb. n.).

Justification for the establishment of the new genus. Head and pronotum morphology of Disconius shelfordi comb. n. differs too widely from other Discotettix species for it to be regarded as a member of the latter genus, so a new monotypic genus is established for this species, Disconius Skejo, Pushkar et Tumbrinck gen. n. Fastigial horns are lower, while the bifurcation of the frontal costa, lateral ocelli and antennal grooves have a much higher position than in any Discotettix species. Unlike FM and high pronotal projections in Discotettix , Disconius gen. n. lacks elevated FM (present as a small tubercle on the anterior pronotal margin); FL1 and FL3 are not strongly projected forwards as in Discotettix , and the strongest projections are ML of the shoulders area (similar to Tegotettix ). The new genus is assigned to the subfamily Scelimeninae and to the tribe Discotettigini stat. resurr. on the basis of the width of the vertex (wide) and the weak elevation of the lateral carinae of the vertex; the typical arrangement of the pronotal projections (FM, MM, MML, ML); armed femora; and not widened hind tibiae and tarsi. The new genus is similar and likely related to the genera Tegotettix and Discotettx, but also superficially resembles Falconius . From Tegotettix and Falconius it can be easily distinguished by widened antennal segments, while from Discotettix , to which it was formerly assigned, it can be distinguished by a number of characteristics stated above. Molecular and comprehensive morphometric comparison of Disconius shelfordi comb. n. with large series of Discotettix , Tegotettix , and Falconius specimens is needed in the future, to elucidate the evolution of this curious taxon.

Composition and distribution. A monotypic genus, including only Disconius shelfordi (Hancock, 1907) comb. n., known only from northern Borneo.

Etymology. Because of the former taxonomic placement within Discotettix , and because of the superficial similarity to certain members of the genus Falconius due to its slender appearance and the shape of the pronotal projections, the names of two genera were combined into Disconius , meaning that this is both Discotettix -like and Falconius -like genus.

Differential diagnosis. For the comparison with Discotettix , from which Disconius gen. n. has been removed, see the justification above, as well as the diagnosis of the genus Discotettix . From the genus Tegotettix (including T. armatus and T. bufocrocodil ) the genus can be separated by head morphology — lateral ocelli positioned higher, frontal costa short before the bifurcation, vertex not bearing high horns, antennae with widened subapical antennal segments, and tibiae not armed. From the genus Falconius , Disconius gen. n. can be separated by the arrangement of the pronotal projections, the lack of flattened hind tarsi, and by widened apical segments of the antennae.

Description.

Head. Frontal costa bifurcation between the compound eyes; scutellum narrower than scapus; upper margin of the antennal groove above the lower margins of the compound eye; lateral (paired) ocelli between the compound eyes; eyes protruded above the vertex Antennae 15-segmented (1 st scapus; 2 nd pedicel; basal 3 rd –7 th elongated; central or subapical 8 th weakly compressed, 9 th elongated and strongly compressed; 10 th compressed; apical segment 11 th small; apical 12 th –15 th reduced, smooth and cylindrical). Vertex wider than a compound eye. Lateral carinae of the vertex in frontal view weakly elevated, medial carina of the vertex visible, anterior margin of the vertex slightly indrawn.

Pronotum. Body robust, the ratio of the humeral angles’ width to the prozonal width more than 3.5. Anterior margin of the pronotum truncated or slightly excised, without strongly elevated FM; prozonal carinae distinct and parallel; extralateral carinae strong, with FL2 as a small elevation; FL3 weak; medial carina continuous along all the pronotum, tuberculated; MM high compressed elevations; PMLs and MMLs distinct; MML2 well developed as a high tubercle; ML triangular protrusion with a tubercle on its tip; interhumeral carinae distinct; interscapular area distinct and with parallel margins; lateral area as wide as the interscapular area; humero-apical, humeral, and lateral carinae with triangular or spine-like projections; VL protruded as a weak spine; paranota triangular; dorsum of the pronotum without Discotettix — characteristic net-like elevations, but still rough.

Legs. Fore and mid femora carinated above, armed with a few small teeth on the dorsal and ventral margins; the dorsal margin of hind femora strongly armed; ventral margin with undulated carinae; the external surface of the hind femora with recognizable transverse ridges; hind tibia finely, densely serrate with numerous small teeth, but without large teeth; distal part of the hind tibia slightly widened, proximal tarsal segment slightly widened; first and the third tarsal segments of the hind legs almost equal in length; pulvilli typical for Scelimenini —first two angular and the third obtuse.