Guntheritettiginae Cadena-Castaneda 2025, subfam. nov.

Subfamily Guntheritettiginae Cadena-Castañeda, subfam. nov. Type genus: Guntheritettix Cadena-Castañeda & Tavares gen. nov. Description. Slender and moderately robust. Face not elongated, subcircular, or ovoid. Vertex wide, about two or three times the width of an eye (Figs. 126C, 127C, 131B, 132C, 136C, 145C, 148C); antennae elongated, with 12– 13 segments (in some taxa, the segments are modified) (Figs. 126A, 126B, 144A, 148A); antennal groves located at the level of the lower margin of the eyes. Medial and lateral carinae of the vertex not produced (Figs. 126A, 127C, 131B, 136C, 144A, 148C), fascial carinae short and narrow, reaching to a third of the frons (rarely to the middle of the face), running parallel. In frontal view, in lateral view slightly projected and rounded. Eyes noticeably separated, rising to the level of the anterior edge of the pronotum; lateral ocelli in the middle of the eyes; central ocellus on the lower margin of the scutellum (Figs. 126C, 132C, 144C, 146C, 148C). Pronotum surpassing the abdomen and apex of the hind femur; anterior edge truncated and posterior one acute or gently truncated (Figs. 126A, 127B, 144B); lower edge of the lateral lobes projecting noticeably towards the sides, triangular in dorsal view, acute or with conspicuous spines (Figs. 129B, 131C, 132B, 137B, 144B, 148B). Lateral inner and median carinae projected or wavy; tegminal sinus undeveloped; humeral carinae poor or not developed. Tegmina small and ovoid (Figs. 128A, 129A, 138A, 144A); hind wings mostly well-developed and reach the apex of the pronotum, or slightly exceed it. Dorsal margin of the fore and mid femora dorsally carinated; tarsi elongated, first segment of the tarsus of the hind leg longer than the third one. Ovipositor valves narrow compared to the taxa of the other subfamilies and smoothly denticulate (Figs. 129A, 132A, 144A). Tribes included. Guntheritettigini trib. nov. and Tumbrinckitettigini trib. nov. Distribution. Madagascar (Maps 9–12). Comparission. Guntheritettiginae subfam. nov. differs from the other subfamilies currently constituted by the following characters: 1) Fascial carinae short (no other group has it that way, nor a similar arrangement of lateral ocelli). 2) The vertex is noticeably broad, comparable to Lophotettiginae, as the shape and arrangement of the eyes. 3) Scutellum narrow, distinguishing it from several Cladonotinae and some Metrodorinae taxa with a wide scutellum. It is also distinguished from the broad scutellum of Lophotettiginae, which, although the fascial carinae are parallel, does not have the typical shape of the Guntheritettiginae subfam. nov. 4) The antennae have a normal development, with 12–13 segments, although elongated, and thin (except Andriana with the last segments dilated), in contrast to short antennae and with noticeably dilated segments like those of Lophotettix Hancock, 1909 (11 segments) or Tripetalocerinae (8 segments). 5) The pronotum has modifications in the form of spines, tubercles, or undulations, not common or homologous with other taxa such as Arulenus Stål, 1877 (currently in Scelimeninae). The lateral lobes of the pronotum expand to the sides in a triangular shape, although some Tumbrinckitettigini trib. nov. have the shape of a sharp spine, straight or curved forward in dorsal view. This character is convergent in several taxa of Tetrigidae and is frequently observable with Scelimenini (Scelimeninae) and, to a lesser extent, in Otumbini trib. nov. and Garciaitettigini trib. nov. (Metrodorinae). Additionally, the tegminal sinus of Guntheritettiginae subfam. nov. is not developed as in other subfamilies. 6) The first tarsal segment of the hind leg is longer than the third. Although this is a debatable character, most taxa have this combination of the character, being different in Metrodorinae, in which, at least in the Neotropical tribes, the character remains stable. 7) The valves of the ovipositor are slender, probably due to the substrate or place of laying eggs, which must differ from other taxa with more robust valves. Thin valves are also observable in Garciaitettigini trib. nov. Remarks. This new subfamily is proposed since the grouped taxa have several characteristics in common that differentiate it from Metrodorinae and the other subfamilies currently defined, as previously mentioned. The taxa are endemic to Madagascar and adjacent islands (Malagasy region). Their differentiation from other Metrodorinae was previously suspected, being considered an informal group (Günther 1939, 1959, 1974; Devriese 1991; Skejo et al., 2020).