Nothybus kuznetsovorum, Galinskaya, Tatiana V. & Shatalkin, Anatole I., 2015

Galinskaya, Tatiana V. & Shatalkin, Anatole I., 2015, New species of Nothybus Rondani, 1875 (Diptera: Nothybidae) from Vietnam with a key to Vietnamese species of the genus, Zootaxa 4012 (3), pp. 581-592 : 585-591

Nothybus kuznetsovorum sp. nov.

(figs 2, 5, 6)

Type material. Holotype. 1 ♂, Northern Vietnam: Phú Thọ prov., Thanh Sơn distr., Xuân Sơn munic.; Xuân Sơn National Park; N 21° 08' 20'' E 104° 56' 15''; h= 300–900 m, 23.X.2014, T.V. Galinskaya leg. ( ZMMU).

Paratypes. Northern Vietnam: 9 ♂, 9 ♀, Phú Thọ prov., Thanh Sơn distr., Xuân Sơn munic.; Xuân Sơn National Park; N 21° 08' 20'' E 104° 56' 15''; h= 300–900 m, 23.X.2014, T.V. Galinskaya leg.; 3 ♂, 2 ♀, ibid, 26.X.2014, T.V. Galinskaya leg.; 3 ♂, 1 ♀, ibid, 23.X.2014, T.V. Galinskaya leg.; 2 ♂, ibid, 18.X.2014, T.V. Galinskaya leg.; 1 ♂,Thanh Hóa prov., Thường Xuân distr., Bát Mọt municip., Xuân Liên National Park, 1,5 km SSW from Ban Vin village, near border with Nghệ An prov., In the forest, epiphytic, near river, N 19° 58' 45'' E 104° 59' 05'' h= 900 m – 1250 m. 31.X.2014, T.V. Galinskaya leg. ( ZMMU).

Diagnosis. The new species is close to Nothybus kempi in having the distal part of vein Cu1 with a brown border and differs from it in the predominantly yellow abdomen. Nothybus kempi has the abdomen black, tergite 1, base of tergite 2 dorsally and tergites 6–8 yellow; while tergite 4 in the new species is yellow or with a narrow black band on the basal margin, tergite 3 has two big triangular yellow spots laterally, and tergites 1 and 2 have yellow bands on lateral margins. A wing of the new species has the oblique medial crossband extending from the anterior wing margin to DM-Cu vein, the crossband expands anteriorly towards the costa, and the transparent crossband between the brown subapical crossband and the brown apical margin is narrow. Nothybus kempi , comparatively, has the oblique crossband extending from the anterior wing margin to vein DM-Cu, the crossband is not widened anteriorly, and the transparent crossband between the brown subapical crossband and brown apical margin is wider than the subapical crossband in cells r2+3 and r4+5. The katatergite and anatergite are yellowishgrey, while the katatergite of N. kempi is black, darker than the anatergite. Surstyli are wide, slightly narrowed apically ( N. kempi has surstyli with a small ventral lobe in apical half (fig. 7 b,d)) (in lateral view).

Description of holotype. Male: Head (figs 2 d,e,f) suborbicular, 1.0 mm long, 1.5 mm wide, 1.3 mm high. Frons above antennae bulging, shining yellow; with two dull velvet black spots placed on each side of anterior frontal region, marking less chitinized anterior part of fronto-orbital plates. Occiput shining yellow with three brown spots: one behind ocellar triangle and two on lateral occipital sclerites. Occiput between medial vertical setae (m vt s) deeply excavated. Eyes in profile 1.05 mm long and 0.76 mm high. Parafacials black. Face slightly concave, upper third of face golden yellow; lower 2/3 with dull oval brownish-black spot on pale yellow background. Clypeus pale yellow. Labrum pale yellow with two brown lateral spots on the labellum. Palpi yellow. Scape and pedicel yellow. Flagellum yellow in basal half and brown in apical half. Scape and pedicel 0.14 mm long. Flagellum 0.26 mm long. Arista 2.5 times as long as flagellum, long plumose, dark brown. Four pairs of long and strong shining black head bristles present. 1 orsa pair on anterior velvet black spots; 1 orss pair; 1 vt i and 1 pocl pair.

Thorax (figs 2 a,b) conspicuously prolonged anterior to fore coxae, 4 mm long, 1.2–1.5 mm wide and 1.2–2.0 mm high; yellow to brownish-black. Mesonotum yellow with wide medial stripe and two very narrow lateral stripes. Medial stripe occupying middle half of mesonotum. Postpronotal lobes brown. Katatergite and anatergite yellowish-grey. Scutellum brown with small yellow spot at apex. Subscutellum blackish-brown dorsally and yellow ventrally. Pleuron yellow with brown stripe on dorsal part of katepisternum. Mesonotum, scutellum, subscutellum and pleuron with bluish-grey microtrichosity. Mesonotum with many longitudinal rows of black setulae. Seven pairs of long and strong bristles present on posterior two fifth of thorax: 1 mpl, 1 npl, 1 sa, 1 pa, 1 dc and 2sc.

Wing (fig. 2g) slightly pointed at apex and strongly narrowed towards base. Axillary lobe and alula absent. Wing membrane hyaline with yellow shine. Cells r1 and basal half of c yellow. Vein R-M with brown border. Wing apex with dark brown pattern, consisting of subapical oblique dark brown crossband and of apical dark margin, divided by narrow light brown crossband. Subapical crossband expanding anteriorly. Light brown region between brown crossband and margin with 3 transparent round spots in a line in cells r2+3, r4+5 and m. Distal part of vein Cu1 with separate elongate brown spot. DM-Cu placed slightly distal to middle of cell r4+5. Halteres white with pale brown apices. Calypteres transparent brownish with brown border. Wing 6.6 mm long, 2.1 mm wide.

Legs. Coxa and trochanter yellow. Apical 1/4 of femora brown, basal 3/4 yellow. Tibiae dark brown. Tarsi brown. Fore basitarsi yellowish white except basal 1/10 (fig. 2h).

Abdomen 3.8 mm long and 0.9 mm wide. Tergite 1 yellow; tergite 2 black with lateral and dorsal yellow bands; tergite 3 black with large triangular yellow lateral spots; tergite 4 totally yellow or with narrow black band on basal margin; tergite 5 totally black; tergites 6–7+8 yellow (figs 2 a,c). Lateral membranes transparent yellow. Sternites narrow, yellow.

Postabdomen symmetrical. Genitalia (figs 5,6) yellow with setulae coloured from dark brown to black. Surstyli not forked, with small projection on inner margin ventrally. Small black mark dorsal to projection. Cerci small, without clear border basally. Cerci covered with long setae, one very large seta situated apically. Subepandrial sclerite well developed, fused with lateral hypandrial lobes. Point 1 in fig. 5e marks the connection of the subepandrial sclerite with hypandrium; point 2 in fig. 5e mark the connection of the hypandrium with the epandrium.

Hypandrium well-developed. Lateral lobes of hypandrium V-shaped, inner lobes connected with postgonite posteriorly; postgonite with blunt membranous apex, slightly elongated dorsally; large curved ventral seta situated in middle of postgonite; two smaller seta situated basally. Phallus consisting of ring-shaped basiphallus and very long ribbon-like distiphallus. Basiphallus consisting of one dorsal sclerite and two lateral sclerites. Dorsally basiphallus connected with epiphallus, consisting of a pair of membranose lobes. Distiphallus with two narrow lateral sclerotized stripes extending from base to apex; apex of the distiphallus with dark brown glans. In dorsal view glans transparent along medial line, probably consisting of paired structures connected by two long narrow transparent processes. Phallapodeme well developed, with wide medial lobes (wings, fig. 6, wphap), fused with hypanrium lateral to hypandrial lobes. Ejaculatory apodeme well developed, situated inside segment 6 and differs from that of N. biguttatus .

Body length 6.0 mm long. Wing length 5.5 mm long.

Remarks. Variability in size has been observed: body length from 6.0 to 8.2 mm; wing length from 5.5 to 6.9 mm.

Female. Similar to male. Tergite 6 yellow medially, black laterally. Preabdomen consisting of seven complete segments. Females with retractible ovipositor. Female terminalia with well developed proctiger and cerci, without oviscape. Variability in size has been observed: body length from 5.5 to 8.0 mm; wing length from 4.8 to 7.0 mm.

Etymology. In honour of A.N. Kuznetsov and S.P. Kuznetsova (Joint Russian-Vietnamese Tropical Scientific and Technological Centre).