Acisoma ascalaphoides Rambur, 1842 —Littoral Pintail

(Figs. 4 F, 5H, 6G, 7E, 8E, 10E)

Material. Madagascar: 3 male, Maroantsetra, Voloina, 30-xii-1971, P. & J. Minet (MNHN); 2 males, Tolagnaro, Mandena, 12-ii-2004 / 19-iii-2004, K. Schütte (RMNH); 4 males, Tolagnaro, Sainte Luce, Akaifira, 02-xii-2006, K. Schütte (ZMUH); 1 male, Tolagnaro, Sainte Luce, S8, forest, marecage, 18-x-2006, K. Schütte (ZMUH); 1 male, Tolagnaro, Sainte Luce, S9, marecage west, 01-iv-2004, P. Razafindraibe (ZMUH); 2 males, Tolagnaro, Mandena, bridge from M15 to M16, 13-x-2006, K. Schütte (ZMUH); 1 male, Tolagnaro, Mandena (Citronelle), 13-x-2006, K. Schütte (ZMUH); 5 males, Tolagnaro, Mandena, 17-iii-2004 / 18-iii-2004 / 19-iii-2004 / 22-iii-2004 / 27-iii-2004, P. Razafindraibe (ZMUH); 1 male, Tolagnaro, Mandena, marecage, 12-ii-2004, K. Schütte (ZMUH).

Male diagnosis. Distinctive species confined to the east coast of Madagascar that appears somewhat intermediate between A. trifidum and the species formerly treated under A. panorpoides . Its unique characters are the (1) uniformly brown antefrons, clypeus, labrum and labium (Fig. 4 F, 5H); (2) largely brown thorax with faint and limited paler markings (Fig. 6 G); (3) mostly 2 cells in Fw triangle, although 37% of examined wings with 1 cell; (4) abdomen that narrows most on S5–6 while S7–10 are slender (Fig. 7 E); (5) ventrally entirely dark abdomen with extensive dorsal white markings only on S3–6, which are solid and clean-cut but not confluent across dorsal carina (Fig. 7 E); (6) narrow lobe of hamule with notched tip (Fig. 8 E); and (7) black dorsum of cerci, not largely white (Fig. 7 E). Similar only to A. trifidum are the (8) more numerous Fw Ax, usually 8½ but occasionally 8 or 9½.

Range and ecology. Known only from littoral forest fragments at the southern (Tolagnaro, formerly Fort Dauphin) and northern (Voloina) ends of Madagascar’s east coast (Fig. 9 B). Only about 10% of the original cover of these forests remains, all in small patches of which only 13% are protected (Consiglio et al. 2006). The species may occur elsewhere along the coast, but as it seems restricted to this habitat, could well be under threat (Schütte & Razafindraibe 2007). The larvae are possibly adapted to more acidic water than A. attenboroughi sp. nov.