Rehniatra, Cadena-Castañeda & Quintana-Arias & Infante & Silva & Tavares, 2025

Cadena-Castañeda, Oscar J., Quintana-Arias, Ronald Fernando, Infante, Ivette Coque, Silva, Daniela Santos Martins & Tavares, Gustavo Costa, 2025, Studies on pygmy grasshoppers: On the current Metrodorinae sensu lato classification (Orthoptera: Tetrigidae) with emphasis on American and Malagasy taxa, Zootaxa 5597 (1), pp. 1-265 : 95-99

Subtribe Miriatrina Cadena-Castañeda & Cardona-Granda, 2015 , nom. resurr., stat. nov.

Emended description. Body medium-sized and slender (12–16 mm). Carinae of the vertex conspicuously produced ( Figs. 63A, 67B, 71D, 74B), and distinguishable dorsally; lateral carinae of the vertex more or less pronounced as a plate ( Figs. 64C, 67C, 70C, 73C); antenna with 14 or 15 segments. Scutellum moderately expanded, and almost narrow, delimited by the fascial carinae with its nearly straight branches ( Figs. 63A, 67A, 71C, 74A). Eyes small compared to other tribe members, occupying a quarter or a fifth of the height of the cephalic capsule in lateral view ( Figs. 64D, 67B, 68B, 71D). Pronotal disc with the anterior region widened and progressively thinned towards the apex, predominantly flat ( Figs. 63B, 64C, 69B, 73C); median carinae sub-elevated, and some species with small undulations in the anterior region ( Figs. 73A, B). Lower margin of the lateral lobes of the pronotum projected to the sides, with the apex triangular ( Figs. 67C, 71B, 74C). Infrascapular area narrow and short. Wings well-developed (except Rehniatra gen. nov. and Grantiatra gen. nov.), reaching the apex of the pronotum or slightly exceeding it ( Figs. 65A, 68A, 70A). Fore and middle femora margins undulated ( Figs. 67D, 74D, 74E); hind femur slender; genicular and antegenicular teeth poorly or moderately developed; first article of posterior tarsi as long as the third ( Figs. 65B, 68A).

Genera included. Miriatra Bolívar, 1906, Brazitettix Silva, 2024 , Rehniatra gen. nov., and Grantiatra gen. nov.

Distribution. Andes of Colombia, Amazon ( Colombia, Peru and Brazil), and Guianese regions (Maps 1–3).

Remarks. Mariatrini included most taxa with prolonged vertex ( Cadena-Castañeda & Cardona-Granda, 2015). Then, Storozhenko (2016) synonymized Miriatrini and established the tribe Cleostratini , keeping a group similar to Miriatrini , but including Cleostratus Stål, 1877 , and additional taxa described by the author. Silva et al. (2017) revalidated Miriatrini by only retaining Miriatra , and the other genera remained in Cleostratini until further study was carried out. Recently, Kasalo et al. (2023a) synonymized Miriatrini , arguing that the characters that diagnosed the tribe could not separate from the establishment of Metrodorini . However, characters are provided here, allowing us to differentiate Miriatrina stat. nov. as a group with subtribe status. A key to genera and species of Miriatrina stat. nov. is provided below.

Key to genera and species of Miriatrina

1. Tegmina and hind wings developed ( Figs. 66A, 68A). Scutellum moderately expanded, with its branches almost straight ( Figs. 67A, 68B, 70E). Antegenicular and genicular teeth developed ( Fig. 69A). Apex of pronotum truncated or rounded. Subgenital plate of the male slender and subtriangular, with a pointed apex................................................. 2

- Tegmina and hind wings absent ( Figs. 71A, 73B). Scutellum narrow, with its branches close together ( Figs. 71C, 74A). Antegenicular and genicular teeth poorly developed ( Figs. 71A, 73A). Apex of the pronotum ending in a point ( Figs. 71B, 73C). Subgenital plate of the male conspicuous globose ( Fig. 72B).............................................. 7

2. Anterior section of the vertex triangular, with the lateral margins serrated in dorsal view ( Figs. 64C, 67C). Fore femur slender and rectangular in shape ( Fig. 67D). Dorsal external area of hind femur without black pits/protuberances ( Figs. 65B, 68A). (Genus Miriatra )..................................................................................... 3

- Anterior section of the vertex rectangular and with smooth lateral edges ( Figs. 70C, 70F). Fore femur moderately widened and ovoid ( Figs. 70A). Dorsal external area of hind femur with black pits/protuberances ( Fig. 70D). (Genus Brazitettix )....... 6

3. Ocelli conspicuous. Transverse carina constricting midway and then expanding, together with the medial carina and frontal costa, ending in a trifurcated structure in frontal view ( Fig. 63A)....................................... M. arawaka

- Ocelli of medium size. Medial carina exceeding the lateral horns or transverse carina, and the apex rounded, without a branching appearance ( Figs. 64D, 67A)............................................................................ 4

4. Medial carinae 3 to 4 times longer than transverse carinae in dorsal and frontal views, finely serrulated margins ( Fig. 64D). Tegmina sub-lanceolate 2.5 times longer than wide ( Fig. 64B)........................................ M. boliviana

- Medial carinae 1.5 to 2 times longer than the transverse carinae in dorsal and frontal views, with margins smooth and without modification. Tegmina ovoid 1.5 times longer than wide...................................................... 5

5. Midline of the pronotum with noticeable undulations on the first anterior third of the pronotal disc ( Figs. 65A, 67B)............................................................................................... M. chalazombra

- Midline of the pronotum without undulations ( Figs. 68A, 69A)........................................ M. producta

6. Anterior margin of the vertex rounded ( Fig. 70C); fascial carenae, with an inverted “V” shape ( Fig. 70B)...... B. roraimae

- Anterior margin of the vertex pointed ( Fig. 70F); fascial carenae and frontal costa widely divergent, forming a scutellate frontal structure with a “U” shape, with the frontal costa converting into almost parallel structures ( Fig. 70E).......... B. paulista

7. Fastigium wider than the width of an eye in dorsal view ( Fig. 71B). Pronotal disc flat, median carinae sub-elevated; humero-apical carina straight and conspicuous ( Fig. 71A). Infra-scapular area shorth and narrow ending at the level of the second to third abdominal segments ( Fig. 71A). Angles of the lateral lobes flattened and projected to the sides, triangular shaped ( Figs. 71B, D). (Genus Rehniatra gen. nov.).............................................. R. brevifastigiata comb. nov.

- Fastigium narrower than the width of an eye in dorsal view ( Fig. 73C, 74C). Median carina moderately elevated, giving the pronotum a tectiform appearance ( Fig. 73A); humero-apical carina curved and poorly differentiated. Infrascapular area widened, ending close to the abdomen apex ( Fig. 73B). Angles of the lateral lobes noticeably expanded to sides and pointed ( Fig. 74C). (Genus Grantiatra gen. nov.).................................................. G. douglasi sp. nov.

Genus Miriatra Bolívar, 1906

Mitraria Bolívar, 1887: 253 (nomen preoccupied).

Miriatra Bolívar, 1906: 392.

Type species: Mitraria producta Bolívar, 1887, by subsequent designation ( Rehn, 1904).

Redescription. Body slightly granulated and slender ( Figs. 64A, 65A, 68A). Head little exserted. In frontal view: vertex wider than 1.5 to 2 times the width of an eye; medial carinae of most species 1.5 to 2 times longer than the lateral ones ( Figs. 63A, 67A) ( M. boliviana 3 to 4 times longer ( Fig. 64D)); frontal costa bifurcation located at the middle of the eyes; scutellum moderately expanded, with its branches nearly straight ( Figs. 63A, 67A, 68B); fascial carinae prominent; ramification of fascial carinae angled; antennae groves located lower than the ventral margin of the eyes, in the middle length of each branch of the fascial carinae ( Figs. 63A, 64D, 67A), and with 14–15 segments; lateral ocelli placed between the inferior part of the eyes, near the base from where each branch of the fascial carinae diverges; medial ocellus located close to the lower margin of the scutellum; palpi with last three segments flattened, first two segments short and nearly cylindrical ( Figs. 63A, 67A). In lateral view: carinae of the vertex prominent and protruding forward between the eyes; face moderately oblique; fastigio-fascial angle little convex in front; fascial carinae slightly emerging between the antennae, above and below slightly sinuate; eyes subglobose, with rounded dorsal surface and almost straight ventral margin, not elevated higher than vertex ( Figs. 65B, 67B).

Thorax. Pronotum greatly surpassing the tip of hind femora; pronotal disc straight anteriorly and acuminated at apex; in most species, pronotal disc flat ( Figs. 63B, 69B) (only M. chalazombra with the mid carina with undulations on the first third of pronotum in lateral view ( Fig. 66A)). Lateral carinae almost straight in dorsal and lateral views; humeral angles concave; angles of the lateral lobes flattened and projected to the sides, triangular-shaped and obtuse; posterior margin of lateral lobe with a mid-undulation ( Figs. 64C, 65C, 67C); infra-scapular area shorth and narrow, ending at the level of the first to second abdominal segments; lateral area poorly developed ( Figs. 64B, 66A, 69A). Wings. Tegmina small and ovoid ( Fig. 67E); hind wings well-developed (macropterous). Legs mostly slender. Fore and mid-femora dorsally and ventrally slightly compressed, with some undulations; fore and mid-tibiae sulcated above ( Fig. 67D). Hind femora with ante-genicular tooth developed; genicular tooth triangular and with apex rounded ( Fig. 64A, 65B, 68A). Hind tibiae toward the apices, not or barely ampliated; first and third segments of the hind tarsi equal in length. Abdomen. Last segments moderately constricted; cerci conical, and reduced; ovipositor valves with mid-sized serrations ( Figs. 67F, 67G, 68D); subgenital plate divided at apex ( Fig. 67H).

Male. Unknown.

Species included. Miriatra producta ( Bolívar, 1887), M. boliviana Günther, 1939 , M. chalazombra Günther, 1939 , and M. arawaka Rehn, 1939 .

Distribution. Amazon and Amazon foothills of Peru , Brazil, and Guyana (Guyanese region) (Maps 1 and 2).

Remarks. When described, this genus originally included M. producta and M. phyllocera (Haan, 1843) (currently in Rostella Hancock, 1913 ). In 1939, Günther described one new species. In the same year, Rehn added two other ones, resulting in four species now included within the genus. Silva et al. (2017) moved Metopomystrum brevifastigiata Cadena-Castañeda & Cardona-Granda, 2015 into Miriatra . However, below, this species is transferred to a new genus.