Digentia viridissima Ngoute & Rowell, 2025, sp. nov.
Creators: name: Oumarou Ngoute, Charly
name: Rowell, C. H. F.
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Orthoptera
Acrididae
Digentia
Digentia viridissima

description: Digentia viridissima sp. nov.
Figs 1, 5 D, 6 C, 7 D, 8 E, 9 C, F, 10 C, F, 12 C, F, 13 D, 17 A – C, 18 A – E, 19 A – E, 20, Tables 3, 4
Types. —
Holotype: CAMEROON • ♂; Division of Valée du Ntem, Ngutadjap; 7-IV-2023; C. Oumarou-Ngoute leg.; specimen N ° 272023 AV; MfN. Paratype: • 1 ♀; same data as holotype; specimen N ° 212023 AV; MfN.
Other material examined. —
21 (13 ♂ and 8 ♀): ♂, Ngutadjap, CAMEROON, 7 - IV- 2023, specimen N ° 262023 AV, C. Oumarou-Ngoute leg., ONC; ♂, Ngutadjap, CAMEROON, 7 - IV- 2023, specimen N ° 242023 AV, C. Oumarou-Ngoute leg., ONC; ♂, Ngutadjap, CAMEROON, 7 - IV- 2023, specimen N ° 232023 AV, C. Oumarou-Ngoute leg., ONC; ♂, Ngutadjap, CAMEROON, 7 - IV- 2023, specimen N ° 252023 AV, C. Oumarou-Ngoute leg., ONC; ♂, Ngoyla, CAMEROON, 27 - V- 2019, specimen N ° 2021101, C. Oumarou-Ngoute leg., RC; ♂, Ngoyla, CAMEROON, IV- 2021, specimen N ° 2021042, C. Oumarou-Ngoute leg., ONC; ♂, Ngoyla, CAMEROON, IV- 2021, specimen N ° 2021040, C. Oumarou-Ngoute leg., ONC; ♂, Ngoyla, CAMEROON, IV- 2021, specimen N ° 2021043, C. Oumarou-Ngoute leg., ONC; ♂, Ngoyla, CAMEROON, IV- 2021, specimen N ° 2021011, C. Oumarou-Ngoute leg., ONC; ♂, Ngoyla, CAMEROON, IV- 2021, specimen N ° 2021008, Oumarou-Ngoute leg., ONC; ♂, Ngoyla, CAMEROON, IV- 2021, specimen N ° 2021010, Oumarou-Ngoute leg., ONC; ♂, Ngoyla, CAMEROON, IV- 2021, specimen N ° 2021007, Oumarou-Ngoute leg., ONC; ♂, Ngoyla, CAMEROON, IV- 2021, specimen N ° 2021004, Oumarou-Ngoute leg., ONC; ♀, Ngutadjap, CAMEROON, 7 - IV- 2023, specimen N ° 222023 AV, Oumarou-Ngoute leg., ONC; ♀, Ngutadjap, CAMEROON, 7 - IV- 2023, specimen N ° 202023 AV, Oumarou-Ngoute leg., ONC; ♀, Ngoyla, CAMEROON, 27 - V- 2019, specimen N ° 2021102, C. Oumarou-Ngoute leg., RC; ♀, Ngoyla, CAMEROON, IV- 2021, specimen N ° 2021047, Oumarou-Ngoute leg., ONC; ♀, Ngoyla, CAMEROON, IV- 2021, specimen N ° 2021067, Oumarou-Ngoute leg., ONC; ♀, Ngoyla, CAMEROON, IV- 2021, specimen N ° 2021012, Oumarou-Ngoute leg., ONC; ♀, Ngoyla, CAMEROON, IV- 2021, specimen N ° 2021002, Oumarou-Ngoute leg., ONC; ♀, Ngoyla, CAMEROON, IV- 2021, specimen N ° 2021003, Oumarou-Ngoute leg., ONC (Fig. 17).
Type locality. —
CAMEROON, Division of Vallée du Ntem, Ngutadjap.
Etymology. —
From Latin, viridissima, which means “ greenest. ” Refers to the external habitus of the species, which is the greenest in the genus.
Description. —
Male. Body of medium size (average L = 19.61 mm; Table 3), integument shiny, rugose on head, pronotum, tergites of mesothorax, metathorax, and the first abdominal tergites.
Head. Antennae filiform, longer than head and pronotum together (average Ant / P = 2.05 mm); fastigium of vertex short, about twice as wide as long, pentagonal, slightly oblique and rugose, frontal ridge well developed; eyes oval, protuberant; interocular space (average IOS = 0.47 mm) slightly wider than antennae scape, with a weak medial furrow.
Thorax. Pronotum cylindrical, lateral carinae absent, medial carinae weak; midline of the disc crossed by three deep transverse sulci, the space between the sulci 2 and 3 slightly wider than metazona; metazona short, about one-fourth of the length of prozona; posterior margin of metazona concave, notched in the midline; anterior margin of pronotum rounded slightly or not at all notched in the midline (Fig. 5 D); prosternal process conical, pointed; mesosternal space about 2 times longer than wide, lobe rounded; metasternal space open, less than half the width of the mesosternal space. Tegmina extremely reduced, minute, narrow, and straight, reaching or slightly exceeding the posterior margin of mesosternal segment (Fig. 7 D); hind femur slender; lower genicular lobe pointed; hind tibia slender, slightly expanded apically (Fig. 8 E), seven to eight external tibial spines, external apical spine of the tibia present, nine internal tibial spines (Table 3); internal spurs larger than external spurs.
Abdomen. Tympanum wide, rounded; the tip of abdomen curved upward. Last abdominal tergite divided in the midline, furcula blunt, with rounded and upwardly inflated margins either side of the midline; supa-anal plate triangular in dorsal view, somewhat elongated distally, with a rounded tip, weak medial longitudinal groove proximally, bounded posteriorly by a very weak transverse ridge that extends across the width of the plate. Cercus flat, compressed laterally, inwardly curved, excised apically, slightly shorter than the subgenital plate (Figs 9 C, F, 10 C, F); subgenital plate conical with rounded upwardly directed apex.
Phallic complex. Phallic complex (Fig. 18 A – D) of medium size. Bridge of epiphallus not divided, anterior margin slightly concave, posterior margin almost straight; outer lophi long, slender, conical, upward curved with rounded tip; inner lophi wide rounded; anterior processes slender, incurved; “ oval ” sclerite almost oval, elongated, with rounded tips (Fig. 19 A – E). Cingular apodemes slender elongated with rounded apex, rami rounded not fused ventrally (Fig. 18 C, D); ventrolateral sclerite laterally flat, tapered towards the tips (Fig. 18 E). Valvular plate robust, celliform, wide in dorsal view with three lobes, the anterior lobe blunt, the posterior edge slightly upturned. Endophallus apically robust and wide; endophallic apodemes slightly slender, lobiform; gonopore process slender, pointed (Fig. 19 F, G). Well-developed endophallic flexure, terminating in an endophallic process abutting the ventral aedeagal sclerite (Fig. 20) that constitutes the apical valve. Ventral aedeagal sclerite robust, wide, with rounded apex.
Female. In general, similar to the male. Female particularities: medium size (average L = 24.18 mm) (Table 3). Tip of abdomen not curved upward; last abdominal tergite without inflated margins; supra-anal plate triangular with rounded apex; cercus conical, incurved, with acute apex, reaching or slightly exceeding the supra-anal plate (Fig. 12 C, F). Dorsal ovipositor valves slightly incurved, smooth, with rounded apex; ventral ovipositor valves wide basally with rounded corner or lobe, strongly incurved in the middle, straight apically, with rounded apex; egg guide straight, pointed, about one-third of the length of ventral ovipositor valves (Fig. 13 D).
Sexual dimorphism. The antennae of D. viridissima are longer in male than in female (Ant male / Ant female = 1.04, and 1.23 after normalization) (Table 3). The male interocular spaces are narrower (IOS male / IOS female = 0.75, and 0.89 after normalization) than the female ones (Table 3). The ratios of the other body dimensions are closely similar in both sexes (Table 3).
Coloration. Male and female (Fig. 17). Body multicolored, predominantly green-yellow. Scape and pedicel of antennae green, flagellum green basally and green-brown apically. Fastigium of vertex green or green-yellow; vertex green or green-yellow with black longitudinal bands either side of the midline extending onto the pronotum, the mesothorax, metathorax, and up to the fifth abdominal segment, reaching the last segment in some females. Eyes blackish in life, fading to brown when dried; frons green or green-yellow, the lower half more yellowish or with yellow spots which extending posteriorly across the genae as a yellow subocular stripe, forming two yellow patches on the ventral margin of the pronotal lobes (Fig. 6 C) and extending rearwards to the mesothoracic and the metathoracic pleura. Distal part of clypeus and labrum green, green-yellow, or yellowish, apical part brown; mandibles and palps green, green-yellow or yellowish. Pronotal disc multicolored, predominantly green or green-yellow with two lateral black stripes that extend dorsally onto the mesothoracic and metathoracic tergites; prothoracic sternum green, mesothoracic and metathoracic sterna red; hind femur predominantly green, upper internal area and medial external area green, basal external area, basal internal area and medial internal area yellowish distally but greenish proximally; genicular lobes black; tibia green-blue, tibial spines green with black tips; tarsi green. Abdominal tergites green or green-yellow with two black longitudinal bands either side of the midline, reaching the last segment in some females; supra-anal plate and cercus green, ovipositor valves green, subgenital plate red.
Distribution. —
CAMEROON, Division of “ Haut-Nyong ”, Ngoyla: 2°17'44"N, 14°13'57"E, altitude 510 m; 2°16'21"N, 14°16'27"E, altitude 505 m; 2°21'13"N, 14°15'20"E, altitude 498 m. Division of “ Valée du Ntem ”, Ngutadjap: 2°42'N, 11°03'E, altitude 560 m; (ONC) (Fig. 1).
Habitat. —
Digentia viridissima sp. nov. and D. fasciata live in humid forest, particularly where it is swampy. In the two reported localities, Ngoyla and Ngutadjap, of the south Cameroon plateau, the species shares its habitat with another Oxyine, Pterotiltus sp., and several Catantopines, Gemenata opilionoides, Pteropera spp. At Ngutadjap, the most abundant plant species were undergrowth taxa such as ferns and herbs (Table 4). Among these, Pteridium aquilinum (Dennstaedtiaceae) covers more than 75 % of the total surface of the site, Palisota hirsuta (Commelinaceae) covers 25–50 %, and the Marantaceae species, such as Marantochloa conferta, Afrocalanthea rhizantha, and Hypselodelphys sp., cover 5–25 % of the total surface (Table 4). The site also has trees and shrubs. The shrub Leea guineensis (Leeaceae) covers between 25–50 %, and Eremospatha macrocarpa (Arecaceae) and Raphia farinifera (Arecaceae) cover 5–25 % of the site. Alchornea floribunda (Euphorbiaceae) and Tabernaemontana brachyantha (Apocynaceae) cover less than 5 %, and Artabotrys insignis var. batesii (Annonaceae), Dicranolepis buchholzii (Thylemeleaceae), Bertiera elabensis (Rubiaceae), Guarea glomerulata (Meliaceae), Musanga cecropioides (Cecropiaceae), and Voacanga sp. (Apocynaceae) are weakly represented (Table 4). The other uncommon tree species include Alstonia boonei (Apocynaceae), Strombosia pustulata (Olacaceae), Pentaclethra macrophylla (Fabaceae - Caesalpinioideae), Leptonychia sp. (Sterculiaceae), and Calpocalix brevibracteatus (Fabaceae - Mimosoideae) (Table 4). The Digentia and Pterotiltus species were usually collected on ferns, but we did not observed Digentia viridissima sp. nov. or D. fasciata feeding on a particular plant. This is likely because the rarity of specimens of these species in the field led us to quickly capture the few seen without taking time to observe their behavior on the host plant.
description: Published as part of Oumarou Ngoute, Charly & Rowell, C. H. F., 2025, Review of the African genus Digentia Stål, 1878 (Orthoptera, Acrididae, Oxyinae), pp. 11-30 in Journal of Orthoptera Research 34 (1) on pages 11-30, DOI: 10.3897/jor.34.126949