Hildegardiini 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 : 221-223

Tribe Hildegardiini Cadena-Castañeda , trib. nov.

Type genus: Hildegardia Günther, 1974 .

Description. Body robust, small to medium size (7.5–13). Head little exserted. In frontal view, face rectangular, and taller than wide; vertex anteriorly truncated into a structure almost at the level of the upper edge of the eyes; medial and lateral carinae not elevated; vertex as wide as the width of an eye or slightly wider. Scutellum narrow and, with the fascial carinae, reaching about half the height of the face; frontal costa fork originating in the middle of the eyes. Eyes small, ovoid, slightly straight at the lower margin, not conspicuously protruding upwards or to the sides, occupying one-fifth of the cephalic capsule. Ocelli diffuse and poorly differentiated, especially the lateral ones, located in the middle of the eyes; median ocellus tiny, close to the scutellum’s lower margin. Antennal groves broad and situated at the level of the lower margin of the eyes ( Figs. 149C , 150C , 151C , 152C , 153C , 154C ); antennae elongated, with 12–13 segments, twice as long as the mid femur, with thickened scape and pedicels, solid and poorly articulated; most antennomeres with extensions at their apex that protrude laterally ( Figs. 153A, B ). Segments of the palps slightly widened and moderately flattened. In lateral view, face almost straight; medial carinae not protruding beyond the eyes, slightly tapering ( Fig. 149A , 150A , 151A , 152A ); anterior margin of the vertex truncate, and dorsum without fossulae ( Figs. 149B , 150B , 151B , 152B ). Thorax. Pronotum thick, broad and robust, conspicuously granular; anterior edge straight or slightly prolonged in the middle, covering about half of the abdomen; posterior margin truncated with three deep undulations ( Figs. 149B , 150B , 151B , 152B , 154B ); median carina of the pronotal disc forming a laterally flattened crest, slightly arched in the anterior region or along its entire length; inter humeral and humero-apical carinae developed and visible; dorsal surface of the pronotum rough with several oblique and transverse undulations or extensions. Lateral lobes of pronotum quadrangular in lateral view, lower margin moderately projecting to the sides, with rounded or somewhat angled apex; tegminal sinus absent; scapular area wide and occupying a good part of the lateral surface of the pronotum; lateral area undeveloped ( Figs. 150A , 151A , 152A ). Wings absent. Legs. Fore and mid femur slightly widened, with some small serrated teeth or blunt lobes mainly on the lower edges and also on the upper ones. Hind femur with some teeth on the upper and lower edges, additionally with foliate teeth on the ventro-external carina, which undulates more conspicuously in the middle and at the distal end of the lower ridge of its outer medial part; antegenicular and genicular teeth conspicuously developed ( Figs. 149A , 150A , 154A ). Hind tibia scarcely ampliated near the apex; the first segment of the hind tarsi longer than the third one. Abdomen. Male: last segments (eighth and ninth) moderately constricted ( Figs. 149A, 149B , 152A ). Subgenital plate cupuliform, as long as or slightly longer than the last abdominal sternite, and with a developed midline and angled apex ( Fig. 153D ). Cerci subcylindrical and moderately thin. Female: last abdominal segment more or less short and stocky, blunt in lateral view. Epiproct lanceolate, with angled apex ( Figs. 150B , 151B , 154D ). Subgenital plate quadrangular, with a small medial prolongation. Valves of the ovipositor protruded from the terminalia, narrow and smoothly denticulate ( Figs. 150A , 154D ).

Genera included. Hildegardia Günther, 1974 only.

Distribution. Mauritius and Reunion islands (Map 13).

Remarks. The species included in this new tribe have an incredible appearance, different from the other taxa of the family. The morphology of the antennae is unique, but at the time, Günther (1974) suggested that the most similar were the antennae of Kraengia Bolívar, 1909 ( Scelimeninae : Discotettigini ), but it is a superficial similarity. He also suggested a possible relationship between Hildegardia and Hyperyboella Günther, 1938 ( Batrachideinae : Bufonidini ), a genus whose antennae were unknown, so their comparison was incomplete.

Additionally, Hildegardia species camouflage themselves among the lichens and bryophytes of these islands (see: Hugel, 2014, fig. 2b) with green colorations and gray or greenish-black spots. Other specimens may have brown coloration, with cream spots, which could simulate bark or rocks ( Fig. 155 ). This coloration is not preserved in museum specimens, so this aspect had not been recorded before Hugel’s contributions (2007, 2014).

Genus Hildegardia Günther, 1974

Hildegardia Günther, 1974: 1000 .

Type species: Hildegardia mauritiicola Günther, 1974 , by original designation.

Remarks. This genus consists of three species: Hildegardia mauritiivaga Günther, 1974 , H. mauritiicola, Günther, 1974 , and H. reuniivaga Hugel, 2007 . A key to species is given below.

Key to species of Hildegardia (modified from Hugel, 2007, 2014)

1. Antennae with 12 segments. Pronotum anterior lateral carinae absent or hardly visible ( Figs. 149B , 150B ). Anterior margin of pronotal disc slightly pronounced towards the front, median carina rising in a ridge, from the anterior to posterior margins of the pronotum ( Figs. 149A , 150A ). Medial area of the hind femur without lateral foliate processes or spiny but with small lappets ( Figs. 149B , 150B ). From Mauritius Island (Maps 13C, E)......................................... H. mauritiicola

- Antennae with 13 segments. Pronotum anterior carinae short but distinct. Anterior margin of pronotal disc straight, with the median carina rising in a crest in the first half of its extension. Medial area of the hind femur with lateral processes foliate or spiny............................................................................................... 2

2. Antennae median articles distally with long spiny protrusions. Dorsal carina of the fore femur with at least two lobes/spines ( Figs. 151B , 152A ). From Mauritius Island (Maps 13C, E)........................................ H. mauritiivaga

- Antennae median articles distally with short blunt protrusions ( Figs. 153A, B ). Dorsal carina of the fore femur wavy in lateral view, without distinct spine or lobe ( Figs. 153B , 154B ). La Reunion Island (Maps 13C, D)................. H. reuniivaga

MAP 13. Distribution of Hildegardia species.

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).

FIGURE 155. Hildegardia reuniivaga Hugel, 2007. Female in live condition. Photo: S. Hugel.