Oedaleus senegalensis (Krauss, 1877)

Figs 69, 70, 71

References for Socotra.

Burr 1903: 412, 418; Popov (in Uvarov and Popov (1957)): 378; Ritchie 1981: 87, fig. 160; Wranik 2003: 324, plate 156.

Diagnostic notes.

Oedaleus senegalensis is a primarily greenish or light brown, sizeable Oedipodine grasshopper with long wings (Figs 69, 70). The pronotum is tectiform, slightly saddle-shaped, with light markings forming an open X. The basal two-fifths of the tegmina are dark brown, transversed with a clear pale band. The distal half is primarily clear with darker cells and blackish veins. The basal half of the hind wing is yellowish, at the tip hyaline, with a narrow black fascia, forming a (nearly) complete band, not reaching the posterior margin of the wing.

Ritchie (1981) revised the genus Oedaleus Fieber, 1853 and identified the taxon present on Socotra as Oedaleus senegalensis .

Distribution and occurrence.

The species occurs from the Canary Islands and West Africa through Sub-Saharan Africa to Arabia, western Russia and south-western India. On Socotra, it is known to occur on several sites scattered over the island (Fig. 71).

Habitat and biology.

O. senegalensis is, like other members of the genus, a geophilous and graminivorous species occurring on dry savannah grasslands (Hemp and Rowell 2020). On Socotra, it has been found in short, grassy vegetation and on bare ground on the coastal plain (Popov in Uvarov and Popov (1957)). Records are from the lower parts of the island from 10–500 m a. s. l. in sparse dwarf shrubland and low Croton - Jatropha shrubland. In 2009 and 2010, we found the species at only two sites: at Qeysoh and in the low hills where Wadi Dineghen flows into Hadiboh Plain. Both sites are characterised by bare ground alternated with sparse and low vegetation. Records are from all seasons.

Bioacoustics.

The related Oedaleus decorus (Germar, 1825) emits quiet, rattling sounds during flight. During rivalry, buzzing sounds are emitted. Courtship consists of 0.5–1.1s sounds, emitted with irregular intervals (Roesti and Keist 2009). On Socotra, sounds emitted by O. senegalensis have not been recorded.