Digentia rufogeniculata
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 rufogeniculata

description: Digentia rufogeniculata (Bolívar, 1911)
Figs 1, 4 A – E, 5 B, 7 B, 8 C, 9 A, D, 10 A, D, 11 A – I, 12 A, D, 13 B, Table 1
= Genditia rufogeniculata Bolívar, 1911 (syn. Hollis, 1975)
Type material. —
Holotype: DEMOCRATIC REPUBLIC OF CONGO • ♀; Africa, West-Central Tropical Africa, Zaire; Le Marinel leg.; MRAC Tervuren KMMA; RMCA ENT 000045089–400 D. [examined].
Additional material examined. —
8 (4 ♂ and 4 ♀) non-type specimens, caught subsequent to the original description (Fig. 4). ♂, Fandria, DEMOCRATIC REPUBLIC OF CONGO, specimen N ° 6852 H, R. P. Hulstaert leg., RMCA; ♂, Ubangi Binga, DEMOCRATIC REPUBLIC OF CONGO, specimen N ° 6853, Dr J. Brédo leg., RMCA; ♂, Bumbuli, DEMOCRATIC REPUBLIC OF CONGO, specimen N ° 1635 CC, Dr J. Brédo leg., RMCA; ♂, Equateur: Bokuma, DEMOCRATIC REPUBLIC OF CONGO, specimen N ° 6852 M, R. P. Hulstaert leg., RMCA; ♀, Oshwe, DEMOCRATIC REPUBLIC OF CONGO, specimen N ° 1635 A, Dr J. Maes leg., RMCA; ♀, Oshwe, DEMOCRATIC REPUBLIC OF CONGO, specimen N ° 1635 U, Dr J. Maes leg., RMCA; ♀, Mondombe, DEMOCRATIC REPUBLIC OF CONGO, specimen N ° X 1912, R. Mayné leg., RMCA; ♀, Bambesa, DEMOCRATIC REPUBLIC OF CONGO, specimen N ° VIII 1934, Dr J. Brédo leg., RMCA.
Redescription. —
The previous descriptions (Bolívar 1911 and Ramme 1929) of the species are noticeably short and mainly based on coloration. We provide here a more detailed description.
Male. Body of medium size (average L = 23.56 mm; Table 1), integument shiny, smooth on genae, head dorsally slightly rugose; pronotum, tergites of mesothorax, metathorax, and the first abdominal tergites rugose.
Head. Head thick; antennae filiform, longer than head and pronotum together (average Ant / P = 2.61); fastigium of vertex short, about twice as wide as long, pentagonal, slightly concave and rugose, frontal ridge well developed; eyes oval, protuberant; interocular space (average IOS = 0.71 mm) slightly wider than antennae scape with weak medial furrow.
Thorax. Pronotum cylindrical, lateral and medial carinae absent; midline of the disc crossed by three deep transverse sulci, the space between sulci 2 and 3 narrower than metazona; metazona short, about one-half of the length of prozona; anterior and posterior margin of pronotum rounded very slightly or not at all notched in the midline (Fig. 5 B); prosternal process long, thin, and pointed; mesosternal space about 2 times longer than wide, lobe rounded; metasternal space open, wider than the half width of the mesosternal space. Tegmina reaching or exceeding the anterior margin of the first abdominal segment, the base not narrowed, apex rounded, strongly veined with reticulation, coarsely areolate (Fig. 7 B); hind femur slightly robust; lower genicular lobe pointed; hind tibia wide apically (Fig. 8 C), eight to nine external tibial spines, external apical spine of the tibia present, nine to ten internal tibial spines (Table 1); internal spurs larger than external spurs.
Abdomen. Tympanum wide, oval; the tip of abdomen curved upward; last abdominal tergite divided in the midline (Fig. 9 D), furcula blunt, with rounded and slightly upwardly inflated margins either side of the midline; supra-anal plate triangular in dorsal view, somewhat elongated distally, with a rounded tip; medial longitudinal groove proximal, bounded posteriorly by transverse ridge that extends across the width of the plate; cercus flat, compressed laterally, inwardly curved, apically forked, longer than the supra-anal plate (Figs 9 A, D, 10 D); subgenital plate conical with rounded upwardly directed apex.
Phallic complex. Phallic complex (Fig. 11 A, B) of medium size. Epiphallus quite robust, bridge wide, not divided, anterior margin and posterior margin convex; a pair of conical and upwardly curved outer lophi, tips acute and slightly incurved; inner lophi weak, lobiform; anterior processes robust, not incurved; oval sclerite wide, subconical (Fig. 11 C – G). Endophallus slender; cingular apodemes in ectophallus slender, elongated with rounded apex, rami rounded not fused ventrally; ventrolateral sclerite laterally flat, tapered towards the tips ventrally, somewhat triangular; valvular plate with three lobes; ventral aedeagal sclerite slender, short with rounded apex; endophallus apodeme wide, lobiform; gonopore process elongated with slightly wide and rounded apex (Fig. 11 H, I).
Female. In general, similar to the male. Female particularities: medium size (average L = 26.53 mm). Tip of abdomen only slightly or not at all curved upwards; last abdominal tergite very slightly or not at all inflated into lobes; supra-anal plate triangular with rounded apex; cercus conical with acute apex, curved outwards, reaching or exceeding the tip of the supra-anal plate (Fig. 12 A, D); dorsal ovipositor valves long, slightly incurved, smooth, with rounded apex; ventral ovipositor valve wide basally, with rounded corner or lobe, slightly incurved in the middle, apically straight, with rounded apex; egg guide straight, pointed, about the half of the length of ventral ovipositor valves (Fig. 13 B).
Sexual dimorphism. Ant male / Ant female is 1.10; after normalization, the male antennae are 1.26 times longer than the female antennae (Table 1). The male interocular space is also slightly narrower (0.95) (Table 1). After normalization, the ratios of the other body dimensions of D. rufogeniculata are closely similar in both sexes. For this species, the foot formula is practically identical in the two sexes; the second tarsal segment is very short (14 % of the foot) as is typical for non-arboreal grasshoppers (Table 1).
Coloration. This is in comparison to Ramme’s description; when we studied the specimens, they were older and drier than when Ramme described them.
Male and female. (Fig. 4) Body multicolored, predominantly olive-green (olive-brown for Ramme). Scape and pedicel olive-green and flagellum blackish; fastigium of vertex olive-green; vertex olive-green; eyes brown (dried); frons olive or ochraceous; clypeus, labrum and palps olive-green. Pronotal disc, mesothoracic and metathoracic tergites olive-green, sulci of pronotum black; prothoracic, mesothoracic and metathoracic sterna olive-green, olive or ochraceous; middle legs olive-green or olive; hind femur predominantly greenish, olive-green or olive (olive-brown or olive for Ramme); when greenish, inner side olive (blueish olive for Ramme). Knee reddish or brownish, with upper genicular lobe blackish; hind tibia green-blue; tarsi dirty olive. Abdominal tergites, supra-anal plate and cercus, ovipositor valves greenish; sub-genital plate olive or ochraceous.
Distribution. —
Democratic Republic of Congo (RD Congo), Le Marinel leg.; Mondombe (9°12'7"N, 22°48'4"E) – DR Congo, R. Mayné leg.; Bumbuli (2°24'32"N, 20°31'19"E) – DR Congo, Dr J. Brédo leg.; Oshwe (2°23'51"N, 19°26'11"E) – DR Congo Dr J. Maes leg.; Fandria (6°7'2"N, 18°59'43"E) – DR Congo, R. P. Hulstaert leg.; Ubangi Binga (2°28'54"N, 20°25'57"E) – RD Congo, Dr J. Brédo leg.; Bambesa (3°26'50"N, 18°51'46"E) – DR Congo, Dr J. Brédo leg.; Equateur: Bokuma (3°25'15"N, 27°54'21"E) – RD Congo, R. P. Hulstaert leg.; Tsluapa: Boende (07°28'11"N, 20°50'20"E) – DR Congo, R. P. Wynants leg.; Equateur: Bokuma (3°25'15"N, 27°54'21"E) – DR Congo, Rév. P. Lootens leg. (Fig. 1).
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