Teuchophorus singaporensis, Grootaert, 2006

Grootaert, Patrick, 2006, The Genus Teuchophorus (Diptera: Dolichopodidae) In Singapore, Raffles Bulletin of Zoology 54 (1), pp. 59-82 : 66-68

Teuchophorus singaporensis , new species

( Figs. 15-19 )

Material examined. – Holotype male: SINGAPORE: Sime forest , 24 Mar.2005 (25026, coll. P. Grootaert, Si 562, ZRC).

Paratypes: SINGAPORE: 1 male, 4 females, Nee Soon , 9 Mar.2005, swamp forest (25006, coll. P. Grootaert, Si 376) ; 3 females, Nee Soon , 9 Mar.2005 (25005, coll. P. Grootaert, Si 393) ; 5 males, 5 females, Sime forest , 24 Mar.2005 (25026, coll. P. Grootaert, Si 562 - male dissected) ; 2 females, Bukit Timah , 16 Mar.2005 (25021, coll. P. Grootaert, Si 515) ; 1 female, Pulau Ubin , Check Jawa, 26 Mar.2005 (25034, coll. P. Grootaert, Si 536) ; 1 male, 4 females, Sime forest , 15 Apr.2005 (25061, coll. P. Grootaert, Si 716) ; 1 female, Kranji (beach forest), 27 Jul.2005 (25254, coll. P. Grootaert, Si 927) .

MALAYSIA: 2 males, 1 female, Pulau Tioman, Salang , 13 Jul.2005, forest (25209, coll. P. Grootaert, Tio 2) ; 4 males, Pulau Tioman, Salang , 13 Jul.2005 (25211, coll. P. Grootaert, Tio 6) ; 7 males, Juara , 20 Jul.2005 (25246, coll. P. Grootaert, Tio 128; extracted for DNA) ; 8 males, 6 females, Johor, Gunung Belumut , 22 Oct.2005, riverbanks in palm oil plantation (25396, coll. P. Grootaert, Si 1098) .

THAILAND: 38 males, 29 females, Phang-Nga province, Thap Put, 23 Oct.1997, (97107, coll. P. Grootaert) population of only T. singaporensis ; 9 males, females (?), Phang-Nga province, Thap Put, 23 Oct.1997, (97107, coll. P. Grootaert) mixed population of T. singaporensis and T. pauper , so females unidentified; 24 males, 5 females, Songkhla province, Ban Huai Mo, 30 Oct.1997, swamp forest (97150, coll. P. Grootaert, RBINS), pure population of T. singaporensis , no T. pauper found.

Diagnosis. – Medium-sized species with yellowish antennae. No acr; 5 dc. Bristles on head, thorax and legs yellow to yellowish brown. Costa not thickened. Prosterna entirely brown with a central black stripe. Mesopleura almost entirely brown. Hypandrium bifurcate, but asymmetric with a short left arm and a longer right arm. In resting position aedeagus shorter than hypandrium.

Description. – Male. Body length: 1.38-1.50 mm; wing length: 1.25-1.30 mm.

Head. Frons and face with greenish black ground-colour, feebly shining. Frons broad. Face wide, at its narrowest point about as wide second antennal segment. Palpi yellowish brown, each with a short brownish yellow, sometimes dark apical bristle. Rostrum yellowish brown. Occiput greenish black, feebly shining. Chaetotaxy as usual, all bristles brownish; 2 very short postocellars. Antenna ( Fig. 15 ) short, yellow; second segment darkened on dorsal surface and narrowly along apical margin; third segment darkened on about apical third. Third segment shorter than wide, with a short, blunt apex. Arista slightly more than three times as long as antenna; basal aristal segment slightly shorter than third antennal segment.

Thorax. Mesoscutum brown, with a greenish shine, becoming paler towards sides; humeri, lower part of notopleura, and a narrow border from wing root unto scutellum brownish yellow. Scutellum brownish with paler border. Mesopleura almost completely brownish; sternopleura yellow; Prosterna brown with a black central stripe. Chaetotaxy as usual, but there are no acr; all bristles brownish or brownish yellow. 5 dc. Scutellum with 2 marginals. No propleural bristle.

Legs, including all coxae, yellow. The preapical posterior comb on the basal tarsomere of the hind legs is contrastingly darkened (the other combs are pale).

Fore leg. Coxa with short pale sparse hairs and a row of short brownish bristles towards apex. Femur with a very short hair-like preapical pv. Tibia about as long as femur, without bristles or serration. First tarsomere without ventral spinule. Length of tibia and tarsal segments (in mm): 0.4: 0.2: 0.09: 0.07: 0.06: 0.07.

Mid leg. Coxa anteriorly and exteriorly with very short hairlets. Femur with 2 minute preapical av and 1 minute preapical pv. Tibia a little longer than femur, with 2 small brown ad; 1 small pd near base; 2 small bristles in apical crown. Length of tibia and tarsal segments (in mm): 0.65: 0.22: 0.13: 0.1: 0.08: 0.08.

Hind leg. Coxa with a very thin and short black exterior bristle. Femur ( Fig. 16 ) with 1-2 preapical av and 1 preapical pv, all very short and weak. Tibia ( Fig. 16 ) hardly longer than femur; 2 (sometimes 3) weak yellowish brown or black dorsal bristles on apical half, and in between them a row of slightly lengthened hairs. First tarsal segment slightly thickened; on its anterior apical rim a fringe of very short brownish hairlets. Length of tibia and tarsal segments (in mm): 0.6: 0.1: 0.2: 0.1: 0.07: 0.075.

Wing hyaline, slightly brownish tinged, with yellowish brown veins. Costa not thickened and not darkened. r4+5 and m1+2 apically very feebly, but distinctly diverging. Tp short, straight, oblique, much shorter than apical part of m3+4 (about 2: 5). Halter yellow. Squama small, yellowish with darkened border, with brownish cilia.

Abdomen dorsally dark brown or brown, feebly shining, with yellowish incisions. Venter and sides yellowish. Hairs and hindmarginal bristles on terga short, dark. Hypopygium ( Figs. 18 and 19 ) large, dark brown, partly blackish, especially the asymmetrical hypandrium contrastingly black and bulging; right arm of hypandrium almost as long as left arm; tip pointing downward and smooth. Aeadeagus rather thick. Two long dorsal epandrial lobes present that surpass the tip of the hypandrial arms, each bearing a small papilla.

Female. Body length 1.3-1.7 mm; wing length 1.2-1.5 mm. Agrees in every aspect with the male. Face a little wider. Legs as in male. Oviscapt with 6 short black acanthae on each hemitergite.

Discussion. – There are three very closely related species in the T. pauper group that should be compared: T. pauper Meuffels & Grootaert, 2003 , T. singaporensis , new species, and T. meieri , new species. All three species lack acrostichals, are of the same size, have yellowish brown antenna, no peculiar bristling on legs and wing without stigma. Although all three species are small in size, and even if there is variation in colouration of the thorax and the bristles, they can easily be recognized in lateral view, by looking at the shape of the hypandrium and the surstyli.

T. singaporensis , new species, and T. pauper are very closely related. Both have 5 equally long dorsocentrals that are yellowish-brown, prosterna entirely brown with a central black stripe and mesopleura almost entirely brown. The most obvious difference is in the genitalia. Both, T. singaporensis and T. pauper have an asymmetrical hypandrium while T. meieri has a symmetrical hypandrium. It is not possible to differentiate T. pauper from T. singaporensis on the somatic characters, but the structure of the male hypopygium is very different: shape of the surstyli, hypandrium, dorsal epandrial lobes and aedeagus.

T. meieri , new species, has 4 equally long, black dc, yellow prosterna with a small central black spot and only the upper third of the mesopleura brown, lower two thirds are yellow. T. meieri has, seen in apical view, a large hypandrium with long, symmetrical arms. Both arms end in a large, bifid tip. The ventral epandrial extensions are also symmetrical and the tip, in lateral view, is very wide. The surstyli are rather short in comparison to the long, digitiform surstyli in T. pauper and T. singaporensis .

Distribution and habitat. – Thailand, Malaysia, Singapore. Rain forest and swamp forest.

Figures

Figs. 15-19. Teuchophorus singaporensis, new species, male: 15, antenna; 16, hind leg; 17, tarsomere 1 of hind leg; 18, hypopygium ventral view, with detail of tip of aedeagus and ventral epandrial lobe; 19, hypopygium lateral view. ae: aedeagus; del: dorsal epandrial lobe; hy: hypandrium; L: left; R: right.