Digentia Stål, 1878

Oumarou Ngoute, Charly & Rowell, C. H. F., 2025, Review of the African genus Digentia Stål, 1878 (Orthoptera, Acrididae, Oxyinae), Journal of Orthoptera Research 34 (1), pp. 11-30 : 11-30

Genus Digentia Stål, 1878

= Genditia Bolívar, 1911 (syn. Hollis, 1975).

= Oxya punctatissima Stål, 1875 (syn. Bolívar, 1905)

Type species. —

Digentia punctatissima ( Stål, 1875) ( NHRS Stockholm).

Subsequent literature. —

Stål 1875: 5: 47; Bolívar 1905: 1: 229; Bolívar 1911: 55: 301; Bolívar 1918: 34: 23; Ramme 1929: 15: 323; Dirsh 1952: 46: 268; Johnston 1956: 256; Kevan 1956: 18: 960; Jago 1964: 8: 190; Dirsh 1965: 237; Dirsh 1970: 120–122; Johnston 1968: 174; Hollis 1975: 31: 223; Otte 1995: 4: 129; Yin et al. 1996: 235; Mestre and Chiffaud 2006: 122.

Revised description of the genus. —

Our description differs somewhat from that of Hollis (1975) who wrote, “ epiphallus with incompletely divided bridge and without ancorae. ” Our specimens of Digentia fasciata and Digentia viridissima sp. nov. have undivided bridges.

Head conical; fastigium rounded and pentagonal from above, wider than long, with or without median longitudinal carinula; frontal ridge sulcate, complete to clypeus; lateral facial keels complete. Eyes moderately bulbous. Antenna longer than combined lengths of head and pronotum. Prosternal process simple, conical with subacute apex. Dorsum of pronotum rugulose and coarsely pitted, rounded or weakly flattened; medial carina weak, lateral carinae absent; mesosternal interspace about as wide as long; disc of pronotum crossed by three deep transverse sulci, the space between sulci 2 and 3 narrower or slightly wider than metazona; posterior margin of metazona rounded slightly or not at all, notched in the midline (Fig. 5 A, B ) or concave and notched in the midline (Fig. 5 C, D ). Tegmina and hind wings very reduced, the former being either minute and not extending beyond mesonotum or scale-like and extending to the first abdominal tergite. All known species are either brachypterous or severely brachypterous. Lower genicular lobe of hind femur spined; hind tibia weakly or moderately expanded in apical part and with acute dorsal margins apically; external apical spine of hind tibia present. In male hind margin of 10 th abdominal tergite with a weak furcula, or if without, then margin expanded dorso-laterally to form upturned lobes.

Phallic complex. Epiphallus with bridge incompletely divided or undivided, without ancorae but with well-developed anterior processes. Outer lophi long and tapering, the tips curved; inner lophi shorter, lobiform; “ oval ” sclerites present, roughly oblong in shape. Unitary ventrolateral sclerite present, extending around the ventral surface of the phallus in the ectophallic membrane, the ends terminating near the proximal ends of the cingular apodemes. Cingular apodemes and zygoma formed in part as sclerotizations in the ectophallic membrane. Rami of cingulum well developed, encircling the endophallus, meeting but not fused together in the ventral midline. Posterior edge of zygoma fused with arch sclerite forming a saddle-shaped valvular plate ( Hollis 1971) with an upturned posterior margin. Endophallus with divergent apodemes proximally, gonopore process robust and bar shaped; long flexures at the distal end of the endophallic plates, ending in rounded endophallic processes that are attached to the robust ventral aedeagal sclerites that form the apical valves. Female ovipositor valves long, slender, smooth or evenly and weakly serrate in apical half.

Figures

Fig. 5. Pronotum, dorsal view, of the Digentia species showing sulci. A. Digentia karnyi; B. Digentia rufogeniculata; C. Digentia fasciata; D. Digentia viridissima sp. nov. Images are under 12 × magnification.