Otumbini Cadena-Castañeda, 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 : 148

Tribe Otumbini Cadena-Castañeda , trib. nov.

Type genus: Otumba Morse, 1900 .

Description. Body generally slender (few taxa robust), small to medium-sized ( 6–15 mm.). Head moderately exerted above pronotum; upper margin of the vertex slightly lower than the level of the upper margin of the compound eye. In frontal view, face ovoid or subrectangular, taller than wide; fastigium rounded or truncate; medial carina of the vertex, slightly elevated or not; lateral carinae moderately elevated, not exceeding the eye level, and usually as long as the medial carina or shorter; vertex narrower or as wide as one eye ( Figs. 98C, 104C, 105C). In lateral view, medial carinae not protruding beyond the eyes. Anterior margin of the vertex rounded or truncated, fastigium of the vertex not forming a long horn and dorsum without fossulae. Antennae groves located at the level of the lower margin of the eyes, rarely lower or in the middle of the face. Antennae usually long, exceeding the middle femur, and sometimes as long as the hind femur, with 12 to 14 segments. Scutellum narrow, or moderately widened, not exceeding the width of the scape; frontal costa mid-sized, with bifurcation usually in the middle of the eyes. Eyes rounded, slightly straight at lower margin, medium-sized or conspicuous, protruding slightly above the vertex, occupying a quarter or a third of the cephalic capsule. Lateral ocelli between the middle part, or close the lower margin 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. 98C, 104C, 105C). Thorax. Pronotum generally slender, reaching or exceeding the tip of the abdomen. Pronotal disc with a straight or rounded anterior margin and a pointed posterior margin, rarely truncated, dorsally almost flat; median carina not very elevated and, if elevated, only sub-elevated in the anterior third of the pronotal disc, looking like a small curvature in lateral view. Lateral lobes of pronotum rectangular in lateral view, lower edge moderately or well projected to the sides, with rounded ( Figs. 104A, 105B, 114B, 115B) or acute apex ( Figs. 98B, 99B, 101B, 102B, 108C, 116C); humeral angle wide, obliquely concave; infrascapular thin and projecting between the second or third abdominal segment (only wide in Platythorus , possibly due to its wingless condition ( Fig. 120A)); lateral area narrow with similar thickness or broader than the infrascapular area, arising on the dorsal undulation of the infrascapular area ( Fig. 119B). Wings. Most species winged, with ovoid tegmina ( Figs. 117A, 119B) (except Otumba with narrow and lanceolate tegmina ( Figs. 104A, 114A)) and hind wings reaching the apex of the pronotum or surpass it. Legs. Fore and mid-femora compressed, elongated, and thin, with undulations on the dorsal and ventral margins, although some taxa have almost straight dorsal and ventral margins ( Fig. 108D). Mid femur carinated above ( Fig. 108E). Hind femur unmodified, without tubercles or lappets; genicular and antegenicular teeth moderately or well-developed. Hind tibia scarcely ampliated near the apex; the first and third segments of the hind tarsi equal in length (rarely, first tarsomere slightly longer than the third). Abdomen. Male: last segments, between the seventh and ninth segments moderately constricted ( Figs. 108F, 110E). Subgenital plate cupuliform, as long as or longer than the last abdominal sternite; apex of subgenital plate rounded or angled and with a pointed apex ( Figs. 108H, 110E). Cerci conical and reduced ( Figs. 108G, 110F). Female: Epiproct triangular or ovoid, with or without medial groove ( Fig. 109C). Subgenital plate mainly rectangular, with a small prolongation at the apex ( Fig. 109E). Ovipositor valves moderately robust, with serrulations of medium length; inferior valves, without being conspicuously covered by the lateral edges of the subgenital plate ( Fig. 109D).

Genera included. Otumba Morse, 1900 , Plesiotettix Hancock, 1907 , Platythorus Morse,1900 , and Brunneritettix gen. nov.

Distribution. Mainly in South America, but with some species from Central America, in southern Nicaragua. The taxa are found mainly in areas of Andean influence, between Peru and Colombia, with few taxa in the Amazon region (Maps 4 and 7).

Remarks. This new tribe groups the remaining Neotropical Metrodorinae with brown, grayish, or blackish colorations. Unlike Garciaitettigini trib. nov., the species of this tribe do not camouflage themselves among bryophytes, and the ovipositor valves are typical shape for the family.