Hercostomus tonguci, Naglis, Stefan & Negrobov, Oleg P., 2017

Naglis, Stefan & Negrobov, Oleg P., 2017, West Palaearctic species of the Hercostomus species-group III (Diptera, Dolichopodidae), with description of a new species from Turkey, Alpine Entomology 1, pp. 33-38 : 33

Hercostomus tonguci sp. n. Figs 1 4

Type material.

Holotype male: Turkey, Akyaka, river banks, salty meadow, 37°03'16"N, 28°19'57"E, 16. 27.v.2011, Bartak & Kubic (CULSP).

Diagnosis.

Antenna black, postpedicel as long as high; arista dorsoapical; face narrow, with dense grey pruinosity; lower postocular setae black; abdominal segments 1-3 with yellow lateral spot; legs including coxae yellow; veins R4+5 and M parallel; CuA about 2.5 times as long as crossvein dm-cu; cercus yellow, with claw-like apical setae.

Description.

Male. Body length (holotype): 2.2 mm, wing length 2.2 mm. Head: frons metallic green, with dense white pruinosity; face (Fig. 2) with dense grey pruinosity, narrowest distance between eyes about as distance between ocellar setae; palpus yellow; proboscis yellowish brown; antennal segments black; postpedicel (Fig. 3) as long as high; arista apicodorsal, pubescent, inserted near apex, apical segment 8 times as long as basal segment; lower postocular setae black. Thorax: mesonotum bright metallic green, with some grey pruinosity; thoracic setae black; 6 pairs of strong dc; 9 10 pairs of long ac; scutellum with 2 strong marginal setae, without lateral setae; 1 strong black ppls; pleura dark metallic green, with grey pruinosity. Legs: including coxae yellow, hind tarsomeres infuscated, setae and hairs black. Fore leg: coxa with some strong anterior setae; femur, tibia and tarsomeres bare; relative podomere ratios: 42:43:24:12:10:7:6. Mid leg: coxa with some anterior and a strong anterolateral setae; femur with a small anterior preapical seta; tibia with 2 small ad, 3 small pd, and a circlet of apical setae; relative podomere ratios: 50:55:29:16:13:8:7. Hind leg: coxa with a strong lateral seta; femur with a small anterior preapical seta; tibia slightly swollen in distal part, with 2 small ad and 3-4 small pd setae, and with a circlet of small apical setae; relative podomere ratios: 57:68:15:25:15:10:7. Wing: hyaline, veins dark brown; basal section of M shorter than distal section; R3+4 and M parallel; M joining costa posteriad of apex; CuAx ratio: 0.35; RMx ratio: 1.45; lower calypter yellowish-white, with brown setae; halter yellowish-white. Abdomen: metallic green shining, with black hairs and setae; tergite 1-3 with a large yellow lateral spot, tergite 8 dark brown. Hypopygium (Fig. 4): epandrium dark brown; cercus yellowish-white, apical border brownish infuscated, with 2 strong, claw-like apical setae in addition to the simple apical and marginal setae; hypandrium dark brown; apicoventral epandrial lobe yellowish-white, with 3 long, sinuate apical setae; surstyli yellowish-white. Female: unknown.

Etymology.

The new species is dedicated to the Turkish dipterist and Dolichopodidae worker Alper Tonguc.

Remarks.

H. tonguci belongs to the species-group III according to Stackelberg (1933) which is defined by the following characters: femora yellow, postocular setae black. In the recent key to Palaearctic species of the species-group III ( Selivanova et al. 2012) the new species runs to H. acutangulatus Yang & Saigusa, 1999 described from China based on the yellow lateral spots on the abdomen. H. tonguci can be distinguished as follows: mesonotum without yellow coloration, first flagellomere as long as high, cercus apically with claw-like setae; wing length 2.2 mm. In H. acutangulatus the mesonotum is partly yellow, the postpedicel is 1.6 times as long as high, the cercus has no claw-like setae apically, and the wing length is 5 mm.