Discobola Osten Sacken, 1865

Podenas, Sigitas, Byun, Hye-Woo & Kim, Sam-Kyu, 2015, Limoniinae crane flies (Diptera: Limoniidae) new to Korea, Journal of Species Research 4 (2), pp. 61-96 : 66

Discobola Osten Sacken, 1865

Discobola Osten Sacken, 1865: 226 ; Kuntze, 1920: 372, 422; Pierre, 1924: 70; Alexander, 1924: 538; Czižek, 1931: 14; Enderlein, 1936: 19; Lackschewitz and Pagast, 1942: 52; Savchenko, 1985: 44.

Limonia (Discobola) Alexander, 1929: 242 , 1950: 194, 1965: 433, 1966: 298, 1967: 76; Edwards, 1938: 20, 23; Coe, 1950: 23; Ishida, 1957: 124; Tjeder, 1958: 144.

Trichobola Osten Sacken, 1869: 97.

Type species ­ Limnobia argus Say, 1824 ( = annulata Linnaeus, 1758 ).

Medium­sized yellowish to brownish crane flies, with wing length ranging from 8.0 to 12.0 mm. Additional cross­vein in central part of cell a 1. Antenna medium long, if bent backwards, ends about at the base of wing. Flagellomeres oval with apical pedicels. Verticils approximately as long as respective flagellomeres. Pronotum distinctly elongate, narrow. Tubercular pits and pseudosutural fovea indistinct. No setae present on katepisternum. Meron very small. Tarsal claw with big subbasal and two or three additional small teeth. Comparative wing width similar to that of most Limoniinae crane flies . Wing distinctly patterned. Usually pattern consists of large concentric spots, sometimes small additional spots present in most cells. Wing venation: vein Sc long, Sc 1 reaching to about branching point of Rs, Sc 2 in most species close to the tip of Sc 1; radial sector long and distinctly arched; R 1 longitudinal, R 2 transverse and far from R 1 tip; discal cell closed, elongate; branches of M beyond discal cell shorter than cell itself; basal deflection of CuA 1 at or slightly beyond base of discal cell. Male genitalia not distinctly wider than abdominal segments. Ninth tergite with slightly concave posterior margin, ninth sternite small, two pairs of gonostyles, inner gonostylus large oval or rounded with distinct spineless rostral prolongation. Sometimes spines or narrow rod­shaped structures present on gonostylus itself. Outer gonostylus narrow, strongly sclerotised and arched at apex, sometimes hook­shaped. Penis simple, elongate. Ovipositor with short and narrow cercus, tip of which distinctly turned upwards. Ninth sternite distinctly elongate. Hypovalvae large and elongate.

Larva cylindrical, tapering behind, covered with short pubescence. Abdominal segments 2 to 7 each with ventral and dorsal creeping welts. Tracheal gills four in number, small, egg­shaped. Spiracular lobes of respiratory disc are reduced. Spiracular field bears two ventral sclerites. Head capsule moderate in size, just lightly reduced, wholly retracted within prothorax. Hypostoma with nine equal teeth, central tooth not protruding, deeply split behind.

Anterior end of pupa large, tapering behind. Pronotal breathing horns small, ear­shaped, flattened. Abdominal segments on basal ring with a transverse row of small hooks which are interrupted at pleura; last segment of male body blunt rounded, in female ­ conical and elongated. Larvae and pupae develop in rotten wood and fungi ( Krivosheina and Krivosheina, 2011).

Discobola is a small genus, which includes only 28 species distributed worldwide. It is best represented in the Australasian / Oceanian Regions (13 species). Genus has also been reported from other regions, as Eastern Palaearctic (9 species), Oriental (7 species), West Palaearctic (4 species), Nearctic (3 species) and Neotropical Regions (1 species), but it is missing in Afrotropical Region ( Oosterbroek, 2015) .

No fossil species belonging to that genus were discovered so far ( Evenhuis, 2014).