Teuchophorus antennatus, Grootaert, 2006

Grootaert, Patrick, 2006, The Genus Teuchophorus (Diptera: Dolichopodidae) In Singapore, Raffles Bulletin of Zoology 54 (1), pp. 59-82 : 65-66

Teuchophorus antennatus , new species

( Figs. 12-14 )

Material examined. – Holotype male: SINGAPORE: Sime forest , 2 Jul.2005, Mal. 1 (25189, coll. P. Grootaert, Si 864).

Paratypes: SINGAPORE: 1 male, Sime forest , 7 Sept.2005, Mal. 1

(25334, coll. P. Grootaert, Si1106); 1 male, Nee Soon, 16 Sept.2005, Mal. 2 (25350, coll. P. Grootaert, Si1107).

Diagnosis. – A species of the T. gratiosus group. Third antennal segment 5.5 times as long as wide; base subrectangular. Arista spine-like, very short, about half as long as the subrectangular swelling of third antennal segment is wide (by. Bristles on head and thorax brown. Acr brown, uniseriate and diverging. Four pairs of marginals on tergite 1.

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

Head. Frons broad, with shining metallic green ground-colour; face concolorous with frons, narrow, near middle as wide as an eye facet. Eye facets enlarged in front and below, small above. Palpi small, 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. 12 ) with basal segment yellow, second segment pale brown, third segment brown, very long, about 5.5 times as long as wide, basally with a subrectangular swelling. Arista very short, about half as long as base of third antennal segment.

Thorax. Mesoscutum and scutellum shining metallic green, but brown on sides (humeri, notopleural depression, postalar calli). Pleurae brown on upper half, but yellow on lower half (sternopleuron, hypopleuron). Long bristles on mesoscutum dark brown. Chaetotaxy as usual. Acr distinct, uniseriate and diverging, 6 dc. Scutellum with 2 marginals.

Legs, including all coxae, yellow.

Fore leg. Coxa with very short, brown hairs, and a row of brown bristles at apex. Femur with minute ventral bristles, and a single longer preapical. A weak posterior preapical present. Tibia about as long as femur, without bristles or serration. First tarsomere without basal spinule. Length femur, tibia and tarsomeres (in mm): 0.58: 0.49: 0.28: 0.14: 0.084: 0.056: 0.056.

Mid leg. Coxa with long brown exterior bristle. Femur with a short, brown preapical av and a strong preapical pv. Tibia with a weak brownish pd on basal third; 3 weak pv and an apical crown of bristles. Length femur, tibia and tarsomeres (in mm): 0.63: 0.63: 0.28: 0.112: 0.07: 0.07: 0.056.

Hind leg. Coxa with a brown exterior bristle (shorter than the one on mid coxa). Femur slightly thickened, without any bristle, except a preapical a and av. Tibia longer than femur, with 4 short brownish pd. Tarsus somewhat curved. Length femur, tibia and tarsomeres (in mm): 0.77: 0.91: 0.07: 0.224: 0.112: 0.084: 0.07.

Wing faintly brownish tinged, with brown veins. Costa not thickened. r4+5 and m1+2 apically slightly diverging. Apical portion of Cu twice as long as tp. Halter yellow. Squama with black border and black cilia.

Abdomen with brown tergites; first sternite yellow, following segments pale brown. Hairs and bristles brownish. Basal tergite with 4 pairs of long black marginal bristles (outmost pair shortest). Hypopygium ( Figs. 13-14 ) brown; cerci brown. Dorsal side of aedeagus near tip sagged. Cercus without long apical bristle. A single long, non-pedunculate lateral epandrial and a short basal epandrial bristle present. Dorsal surstylus with a short dorsal bristle.

Female unknown.

Discussion. – The new species is closely related to T. trangensis Bickel, 1999 . Both have a very long third antennal segment with a very short arista and the base of the third antennal segment has a peculiar subrectagular broadening. In T. trangensis the arista is somewhat longer than the width of the third antennal segment, whereas in the new species the arista is shorter: about half as long as the width of the third segment. In T. trangensis both basal antennal segments are yellow, while only the scape is yellow in the new species. The male genitalia of T. trangensis are not illustrated, but Bickel states (l.c.) that the genitalia of T. trangensis are similar to those of T. gratiosus . The latter has a very long aedeagus, and two long, lateral epandrial setae on a tubercle. The new species has a short aedeagus with a sagged tip and only one lateral epandrial seta. Although T. trangensis and the new species are morphologically very similar, we consider the morphological characters as sound enough to distinguish them as separate species. For a further comparison with T. temasek and T. neesoonensis , I refer to the key and the descriptions above.

Distribution and habitat. – Singapore. Swamp forest.

Figures

Figs. 12-14. Teuchophorus antennatus, new species, male: 12, antenna; 13, hypopygium ventral view; 14, hypopygium lateral view.