Teuchophorus acuminatus, Grootaert, 2006

Grootaert, Patrick, 2006, The Genus Teuchophorus (Diptera: Dolichopodidae) In Singapore, Raffles Bulletin of Zoology 54 (1), pp. 59-82 : 72-73

Teuchophorus acuminatus , new species

( Figs. 28-30 )

Material examined. – Holotype male: SINGAPORE: Nee Soon (Lower Peirce Reservoir), 27 Apr.2005 (25091, coll. P. Grootaert, Si 783).

Paratypes: SINGAPORE: 1 male, Nee Soon (Lower Peirce Reservoir), 27 Apr.2005 (25094, coll. P. Grootaert, Si 789) ; 1 male, Nee Soon , 19 Aug.2005 (25297, coll. P. Grootaert, Si 952) ; 1 male, Nee Soon , 7 Sept.2005 (25323, coll. P. Grootaert, Si 1052) .

Diagnosis. – Third antennal segment nearly 1.5 times as long as wide: basal part wide, with a fine, elongated tip. No acr. No stigma . No ventral bristles on femora.

Description. – Male. Body length: 1.75 mm; wing length: 1.5 mm.

Head. Frons broad, with shining metallic green ground-colour; face concolorous with frons, narrow, near middle as wide an eye facet. Eye facets enlarged in front and below, small above. Palpi small, yellowish-brown, with a black apical bristle. Rostrum brown. Occiput shining metallic green. Chaetotaxy as usual; a pair of long brown ocellars and verticals, 2 small postocellars. Postocular cilia uniseriate, short, brown. Antenna ( Fig. 28 ) with all segments yellowish-brown; third antennal segment not triangular, but rather onionshaped with a slender point; almost 1.5 times as long as wide. Thorax. Mesoscutum and scutellum brownish in ground-colour, with a metallic green shine. Pleura with mesopleura yellowish-brown; sternopleura and hypopleura contrastingly pale yellow; pteropleura brown. Long bristles on mesoscutum dark brown. No acr, 5 dc. Scutellum with 2 marginals.

Legs yellow, without distinct bristles. Femora without ventral bristles. No indication of a basal spine, or a hair on a tubercle on fore metatarsus. Fore leg: No indication of a basal spinule or hair on tarsomere 1. Length femur, tibia and tarsomeres (in mm): 0.42: 0.42: 0.36: 0.11: 0.07: 0.06: 0.06.

Mid leg: Length femur, tibia and tarsomeres (in mm): 0.53: 0.59: 0.39: 0.27: 0.084: 0.07: 0.07.

Hind leg: Length femur, tibia and tarsomeres (in mm): 0.63: 0.64: 0.11: 0.252: 0.14: 0.098: 0.07.

Abdomen. Tergites brown, sternites pale brown. First tergite with short marginals only (not long as in T. temasek and the other species of the T. gratiosus group). Male genitalia large, elongated. Hypandrium and aedeagus asymmetrical ( Fig. 29- 30 ).

Female unknown.

Etymology. – The name acuminatus refers to the pointed tip of the third antennal segment ( acuminatus Lat. for pointed).

Discussion. – The shape of the tip of the third antennal segment suggests that T. acuminatus , new species, might belong to the T. gratiosus group. In contrast to the T. gratiosus group, the genitalia are large and there are no long marginal bristles on the first tergite. Because of the absence of the acrostichals, the rather pale mesoscutum and the asymmetrical hypandrium, T. acuminatus , new species, is provisionally placed in the T. pauper group.

Distribution and habitat. – Singapore. Riverbanks in rain forest.

Figures

Figs. 28-30. Teuchophorus acuminatus, new species, male: 28, antenna; 29, hypopygium ventral view; 30, hypopygium lateral view.