Hildegardiinae 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 : 214-221

Subfamily Hildegardiinae Cadena-Castañeda , subfam. nov.

Type genus: Hildegardia Günther, 1974 .

Description. Body robust ( Figs. 149–154 ). Face elongated, rectangular, taller than wide. Vertex as wide as one of the eyes ( Figs. 149C , 150C , 151C , 152C ). Antennae elongated, with 12–13 segments, more than twice the length of the middle femur; scape and pedicels thickened, strong, and poorly articulated; most antennomeres with extensions at their apex that protrude laterally ( Figs. 153A, B , 154A, B ); antennal groves located at the level of the lower margin of the eyes. Medial and lateral carinae of the vertex not produced, fascial carinae reaching about the middle of the face, branches running parallel in frontal view; in lateral view rounded and slightly projected ( Figs. 149C , 150C , 151C , 152C ). Eyes ovoid and narrow in lateral view, rising slightly above the anterior margin of the pronotum ( Figs. 150A , 151A , 152A ); ocelli very diffuse and poorly differentiated, especially the lateral ones ( Fig. 149C , 150C , 151C , 152C ). Pronotum broad, and brachypronotal, ending in a wavy edge, leaving half or a third of the abdomen visible; lower margin of the lateral lobes of the pronotum slightly projected to the sides and rounded or slightly angled in dorsal view ( Figs. 149B , 150B , 151B , 152B , 154B ). Median carina of the pronotal disc somewhat arched in the shoulder region or along its entire length; tegminal sinus, tegmina, and hind wings absent ( Figs. 150A , 151A , 152A ). Fore and mid legs slightly widened, with some small sawteeth or blunt lobes on the lower margin and usually also on the upper ones; first tarsomere of hind leg conspicuously elongated, usually longer than mid and hind tarsi together. Valves of the ovipositor protruded from the terminalia, narrow and smoothly denticulate ( Figs. 150A , 154A ).

Tribes included. Tribe Hildegardiini trib. nov. only.

Comparission. Hildegardiinae subfam. nov. differs from the other subfamilies currently constituted by the following characters: 1) The fascial carinae is very narrow; the other groups tend to have some degree of divergence, and few taxa have a similar appearance. 2) The vertex is moderately narrow and constitutes a complete anterior margin, the medial or lateral carinae are not protruding. A similar shape is observed in some species of the genus Tetrix Latreille, 1802 . 3) Practically almost all tetrigids have developed ocelli, which vary in their position, but in this new subfamily, the ocelli are diffuse, reduced, and almost invisible. This is a character that allows easy distinction between the other subfamilies. 4) The antennal groves are wider than the average for the family, the scape and pedicellus are conspicuously thickened, and the other segments of the antenna are poorly articulated, with extensions at the apex from the fifth segment. This morphology of the antenna is not comparable with other known genera of tetrigids. 5) The antennae have 12–13 segments; a similar number have been found in Mucrotettigina stat. nov., Guntheritettiginae subfam. nov. and some Cladonotinae s. l. However, the structure of the antenna is different. These taxa have few segments in the antenna; likewise, the length is short, barely exceeding the middle femur. Hildegardiinae subfam. nov., despite having fewer antennal segments than the family’s average, these are elongated and exceed almost twice the length of the middle femur. 6) The pronotum is rugose, and the apex is truncated, not covering the abdomen completely. Such shape of pronotum is similar to taxa from different groups, mainly Procytettix Bolívar, 1912 and Amphinotus Hancock, 1915 . However, the distributional closest forms are Isandrus Rehn, 1929 , and Storozhenkoium gen. nov. 7) The lower margin of the lateral lobes of the pronotum are not conspicuously projected to the sides but rather moderately projected, like some Tetriginae . 8) The first tarsal segment of the hind leg is longer than the third, differentiating it from the Metrodorinae , where Hildegardia is included to date. This character behaves stably in most American Metrodorinae , which is included in its comparison here. 9) The ovipositor valves are slender. This must be due to the shape and place of posture, which must differ from other taxa with more robust valves. Thin valves are also similar in Guntheritettiginae subfam. nov. and in American Garciaitettigini trib. nov. Although the ovipositor of the Hildegardiinae subfam. nov. stands out more at its base than in these last two taxa.

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 the islands of Mauritius and Reunion. On these islands, there are already examples of suprageneric taxa that are endemic, for example, the family Pyrgacrididae (Acridoidea) ( Eades, 2000; Hugel, 2005, 2014), and in the Malagasy region, the subfamily Malgasiinae ( Mogoplistidae : Grylloidea) ( Gorochov, 2014). These areas have had long isolation that has allowed the diversification of these taxa. In this new subfamily, a single monogeneric tribe with three species is included, described below.

Figures

FIGURE 149. Hildegardia mauritiicola Günther, 1974. Male holotype. A. Habitus in lateral view. B. Habitus in dorsal view. C. Frons. D. Labels. Photos: J. Tumbrinck.

FIGURE 150. Hildegardia mauritiicola Günther, 1974. Female paratype.A. Habitus in lateral view. B. Habitus in dorsal view. C. Frons. D. Labels. Photos: J. Tumbrinck.

FIGURE 151. Hildegardia mauritiivaga Günther, 1974. Female holotype. A. Habitus in lateral view. B. Habitus in dorsal view. C. Frons. D. Labels. Photos: J. Tumbrinck.

FIGURE 152. Hildegardia mauritiivaga Günther, 1974. Male paratype. A. Habitus in lateral view. B. Habitus in dorsal view. C. Frons. D. Labels. Photos: J. Tumbrinck.

FIGURE 153. Hildegardia reuniivaga Hugel, 2007. Male holotype. A. Habitus in lateral view. B. Habitus in dorsal view. C. Frons. D. Terminalia. E. Labels. Photos: C. Hervé (MNHN).

FIGURE 154. Hildegardia reuniivaga Hugel, 2007. Female paratype. A. Habitus in lateral view. B. Habitus in dorsal view. C. Frons. D. Terminalia. E. Labels. Photos: C. Hervé (MNHN).