Metrodorini

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 : 11-12

Tribe Metrodorini Bolívar, 1887

Type genus: Metrodora Bolívar , 1887.

Emended description. Body mostly robust ( Figs. 1A, 4A, 12A, 60, 73), but with slender species ( Figs. 64, 68), and small to medium size species (4–16 mm.). Head little exserted (i.e., top of head slightly surpassing the anterior margin of pronotum in lateral view); upper margin of the vertex approximately at the level of the upper margin of the compound eyes; vertex approximately two or more times wider than the eye; carinae of the vertex produced, with lateral carinae forming more or less pronounced horns and medial carina visibly compresso-elevated (i.e., slender and elevated) ( Figs. 1D, 7A, 29A), extremely in Miriatra ( Figs. 63A, 64D, 67A, 68B). In lateral view, medial carina usually protrudes beyond the eyes, at least slightly visible ( Figs. 26B, 34B, 47B, 67B) (in Metrodora s. str. and Platytettix stat. resurr. not protrudes ( Figs. 1A, 10B)). Anterior margin of the vertex rounded; fastigium of the vertex not forming an elongated horn, dorsum without fossulae ( Figs. 1E, 10C, 67C). Antennal groves located below the lower margin of the eyes, and antennae usually short, with 10–15 segments ( Figs. 10C, 22C, 67B). Scutellum mostly wide 1.5–3 times wider than scape ( Figs. 10A, 26C, 34A), rarely narrow; frontal costa mid-sized, bifurcation variable from around the mid-level of the eyes to below the ventral margin of the eyes ( Figs. 1D, 22A, 57A, 71C). Eyes subglobose, with rounded dorsal surface and almost straight ventral margin, occupying a quarter or a fifth of the cephalic capsule in lateral view. Lateral ocelli between the middle or inferior part of the eyes, near the base from where each branch of the fascial carinae diverges; medial ocellus close to the lower margin of the scutellum; palpi with last three segments flattened, first two segments short and nearly cylindrical ( Figs. 1D, 10A, 22A, 26C, 34A, 57A, 71C). Thorax. Pronotum mostly robust (slender only in Miriatra ( Figs. 64, 66, 68A)); variable in shape; median carina with different elevations, forming crests, humps ( Figs. 10B, 12A, 26A, 60B), or flat ( Figs. 30A, 42A); dorsal surface of pronotum, between the carinae, granulate, median carina continuous from the anterior margin to the posterior apex, with anterior margin straight (few taxa have it extended towards the front) and apex truncated or acute ( Figs. 1C, 9B, 21B, 60A, 66B). Lateral lobes of the pronotum, in lateral view, quadrangular; in dorsal view lower margins mostly well-projected to the sides, directed slightly sidewards, and with rounded or acute apex ( Figs. 1E, 10C, 30B). Humeral angle wide, obliquely concave; infrascapular area wide (narrow only in winged species), with different lengths, reaching between the third and ninth abdominal segment in lateral view; lateral area arising on the dorsal undulation of the infrascapular area, with similar width and reaching the apex in lateral view (although in some taxa the lateral area is poorly developed). Wings. Most species apterous, with few exceptions, such as Miriatra (hind wings reaching the apex of the pronotum ( Figs. 66, 69)) and † Electrotettix (rudimentary hind wings). Legs. Fore and mid-femora compressed, with or without conspicuous undulations, sometimes forming some prolongations. Mid-femur dorsally carinated. Hind femur with uniform coloration on the external surface; genicular and antegenicular teeth moderately or well-developed ( Figs. 12A, 19A, 26A) (poorly developed only in Rehniatria gen. nov. ( Figs. 71A, 72)). Hind tibia scarcely ampliated near the apex; first and third segments of the hind tarsi equal in length.

Abdomen. Male: last segments constricted in different levels, and tapering dorsally, joining towards distal portion ( Figs. 8B, 11B, 16F); penultimate sternite variable, longer or as long as the subgenital plate; cerci conical and reduced ( Figs. 8A, 11D, 16G). Subgenital plate short, cupuliform, apex rounded ( Figs. 8C, 11B, 16H) ( Rehniatria gen. nov. with a conspicuous incision at the apex ( Figs. 72B), and Bolivaridora gen. nov. with a small mid notch ( Figs. 51H)). Female: epiproct triangular or ovoid, with or without medial groove ( Figs. 18C, 22F). Subgenital plate of variable shape, mainly quadrangular ( Figs. 18E, 22H, 39D, 67H). Lower valves of ovipositor covered or not by the lateral edges of the subgenital plate; valves armed with medium-sized teeth ( Figs. 18D, 22G, 67G).

Remarks. Recently, the tribe was delimited by Kasalo et al. (2023a). The diagnosis provided by the authors is useful for differentiation with the other suprageneric taxa of the subfamily, and they also synonymized the tribes Miriatrini and Mucrotettigini under Metrodorini . In this contribution, specimens from different genera and species were reviewed to analyze additional characters, and we partially agree with Kasalo’s et al. (2023a) proposal. We included the synonymized tribes as subtribes, which are differentiated in the following taxonomic key.