Teuchophorus dimorphus, 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 : 199-200

Species 31: Teuchophorus dimorphus sp. nov. (male and female) (figures 136–140)

Etymology. Gr. dimorphos, ‘two-formed’, alluding to the different appearance of male and female.

Diagnosis. A species exhibiting a strong sexual dimorphism: abdomen of female pale yellow, unsclerotized, except sixth tergum and all sterna. No stigma. Antenna short; first and second segments dark brown, third segment dusky yellow, pointed, about as long as deep. Hind femur anteroventrally with only some short hairs and one small bristle near apex; hind tibia with a row of five dorsal bristles of unequal length, without ventrals. Mid tibia with one av.

Material examined. Type material: Indonesia, Irian Jaya, Topo , forest near river (pools, muddy areas), 24 April 1997,    male,      36 males, 21 females (No. 970034, leg. P. Grootaert and Ph. Hoyois) .

Male

Body length 1.35–1.5 mm; wing length 1.15–1.25 mm.

Head. Frons with shining dark metallic green ground colour. Face with greenish black ground colour, at its narrowest point (a little below middle) slightly narrower than depth of third antennal segment. Palpi yellowish brown, with few, short black hairs and a black apical bristlet. Rostrum dusky yellow. Occiput shining greenish black. Chaetotaxy as usual; two tiny postocellars. Postoculars uniseriate, black. Antenna (figure 136): short; first and second segments dark brown, third segment yellow or dusky yellow, pointed, about as long as deep. Arista dorsal, inserted at middle of third antennal segment, very shortly pubescent, about three times as long as antenna. Basal aristal segment a little shorter than third antennal segment.

Thorax. Mesoscutum and scutellum with shining dark metallic green ground colour. Pleurae brown, with a large unsclerotized, yellowish area below wing root. Chaetotaxy as usual. No propleural bristles.

Legs. Legs, including coxae, yellow; mid coxa with a brown longitudinal stripe.

Fore leg. Coxa anteriorly with few, very short, brown hairs, becoming longer and bristle-like at apical rim. Femur without bristles, apart from a minute preapical pv. Tibia a little shorter than femur, with a short, inconcpicuous dorsal serration. First tarsal segment, ventrally at base, with two very small black bristlets. Length of tibia and tarsal segments (in mm): 0.32:0.17:0.07: 0.06:0.05:0.06.

Mid leg. Coxa without bristles. Femur with weak preapical av and pv. Tibia about as long as femur; two ad, one pd, one short av, a few short apicals. Length of tibia and tarsal segments (in mm): 0.45:0.19:0.1:0.08:0.06: 0.07.

Hind leg (figure 137). Coxa with a weak, black exterior bristle. Femur anteroventrally, just before tip, in front of the preapical av, with one weak, short bristle, preceded by a few short, weak hairs. Tibia about as long as femur, with about five dorsal bristles of unequal length; three of these bristles are longer, and the longest of them is inserted just beyond middle of tibia; no ventral bristles. Length of tibia and tarsal segments (in mm): 0.45: 0.12: 0.13:0.08:0.06: 0.06.

Wing. Wing (figure 138) hyaline. No stigma; costa not thickened. r4+5 and m1+2 slightly diverging distally. Length ratio of basal and apical parts of m1+2 about 7:9. Halters yellow. Squamae yellow, with narrow black border, and black cilia.

Abdomen. Terga largely brown or dark brown; first tergum yellow. Sterna brownish. Hairs and hind-marginal bristlets on terga very short, black. Sterna with very short black hairs. Hypopygium (figure 139) brownish, brownish yellow or partly yellow, with pale yellow cerci, that reach to tips of surstyli. Surstyli close together, narrow, pointed, blackish.

Female

Body length 1.15–1.6 mm; wing length 1.15–1.3 mm.

Face hardly wider than in male. Antenna shaped and coloured as in male. Serration of fore tibia very inconspicuous. Hind leg feebly browned from apex of femur onwards. Hind femur with very short anteroventral bristlets and hairs. Abdomen (figure 140) largely unsclerotized, yellow; only sixth tergum sclerotized, brown or dark brown. Sterna sclerotized, brown or dark brown. Oviscapt yellow, with eight black acanthae.