Teuchophorus gymnogynus, Meuffels & Grootaert, 2004

Meuffels, Henk & Grootaert, Patrick, 2004, The genus Teuchophorus in South-East Asia and New Guinea, description of new species, species-groups and their phylogeny (Insecta, Diptera, Dolichopodidae), Journal of Natural History 38 (2), pp. 143-258 : 202-204

Species 33: Teuchophorus gymnogynus sp. nov. (male and female) (figures 146–150)

Etymology. Gr. gymnós, ‘naked’, and gynè, ‘female’, alluding to the unsclerotized abdomen of the female.

Diagnosis. A species exhibiting a striking sexual dimorphism: abdomen of female pale yellow, unsclerotized, apart on first tergum and a narrow anterior border of second tergum, and on most sterna. No stigma. Antenna brownish black, short, but with a rather large third segment. Hind legs largely dark brown, fore and mid legs dusky yellow to brown. Hind femur of male ventrally with a row of hairs on whole length. Hind tibia with three dorsal bristles, without ventrals. Mid tibia with one av. Halters darkened.

Material examined. Type material: Indonesia, Irian Jaya, Nabire , km 61.7, river banks in swamp forest, shaded and sun-lit areas, 25 April 1997,    male and      three males, three females (No. 970040, leg. P. Grootaert and Ph. Hoyois) .

Male

Body length 1.8 mm; wing length 1.6 mm.

Head. Frons and face with feebly shining black ground colour. Face at its narrowest point (below middle) slightly narrower than depth of third antennal segment. Palpi brownish black or brown, with short black hairs and a black apical bristle. Rostrum brownish yellow. Occiput black. Chaetotaxy as usual; two minute postocellars. Postoculars uniseriate, black. Antenna (figure 146): short, brownish black. Third segment 1.5 times as deep as second segment, blunt-tipped, deeper than long. Arista dorsal, very shortly pubescent, thin, nearly four times as long as antenna.

Thorax. Thorax, including scutellum and pleurae, with dark brown ground colour, feebly shining. Chaetotaxy as usual; no propleural bristles.

Legs. Fore coxa brown or yellowish brown; mid and hind coxae dark brown. All trochanters brownish yellow. Fore and mid legs brownish yellow or yellowish brown; hind leg darker, dark brown.

Fore leg. Coxa anteriorly with black hairs; at apical rim a row of black hairs, including one hair-like bristle. Femur without bristles, apart from a very short, hairlike, preapical pv. Tibia nearly as long as femur, without bristles or serration. First tarsal segment ventrally at its base with two minute spinules. Length of tibia and tarsal segments (in mm): 0.45:0.25:0.11: 0.09: 0.08:0.09.

Mid leg. Coxa without bristles, bearing only hairs. Femur without bristles, apart from small preapical av and pv. Tibia about as long as femur; two ad, one pd, one rather strong av, some apicals. Length of tibia and tarsal segments (in mm): 0.55: 0.29:0.14:0.12: 0.08:0.1.

Hind leg. Coxa with black ecterior bristles. Femur (figure 147) ventrally, on whole length, with a row of hairs, most of which are more than half as long as diameter of femur. Tibia (figure 147) slightly longer than femur; three fairly strong dorsal bristles; a few short apicals; no ventrals. First tarsal segment ventrally shortly bristly haired, with a short apical spinule. Length of tibia and tarsal segments (in mm): 0.7:0.15: 0.2:0.15:0.1:0.1.

Wing. Wing (figure 148) hyaline, very feebly brownish tinged. No stigma; costa not thickened. r4+5 and m1+2 slightly diverging towards their tips. Length ratio of basal and apical parts of m1+2 about 5:8. Halters brown, sometimes with yellowish stem. Squamae dark brown, with black cilia.

Abdomen. Abdomen with dark brown ground colour. Hairs and hind-marginal bristlets on terga short, black. Sterna with short black hairs. Hypopygium (figure 149) dark brown, apically more yellowish; cerci small, yellowish, not reaching tip of hypopygium.

Female

Body length 1.7–1.9 mm; wing length 1.7–1.8 mm.

Face a little wider than in male. Third antennal segment transverse, nearly without apex, more than 1.5 times as deep as long. Legs coloured as in male. Hind femur without ventral row of hairs. Abdomen (figure 150) largely pale yellow; dorsally only first tergum and a narrow anterior border of second tergum dark brown, sclerotized; ventrally the dark brown colour reaches to hind margin of fourth sternum. Oviscapt yellow, with eight(?) short, black acanthae.