Hybos stigmaticus PLANT 2013, sp. nov.
Creators: name: PLANT, ADRIAN R.
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Hybotidae
Hybos
Hybos stigmaticus

description: Hybos stigmaticus sp. nov.
(Figs 174–178, 274, 300)
Type material. HOLOTYPE ♂: THAILAND Chantaburi Province, Khao Kitchakut National Park, 12°53''09'N, 102°06''40'E, 102 m, 1.vii.2008, netted, A. R. Plant (QSBG). PARATYPES: 4♂, 5♀, same data as holotype, Khao Kitchakut National Park, 28.xii.2007, 21.xii.2008, 22.xii.2008, 24.xii.2008, 25.xii.2008, 26.xii.2008, N. Vikhrev; 2♂, 3♀, Hotel Krating Country Resort, 12.822623°N, 102.127352°'E, 8.ii.2009, A.L. Ozerov: 3♂, 4♀, Mukdahan Province, Phu Ha Kam, dry evergreen forest and stream, 16°25.1'N 104°24.6'E, 180 m, 16.xi.2009, A.R. Plant: 1♂, Nakhon Si Thammarat Province, Namtok Yong NP, Nature trail, 8°10.351'N, 99°44.519'E, 100 m, 12–13.viii.2008: 1♀, Surat Thani Province, Khao Sok National Park, Klong Morg Unit, 8°53.725'N, 98°39.025'E, 87 m, 13– 20.i.2009 (ZMMU, NMWC, QSBG).
Etymology. The specific epithet refers to the strongly marked stigma of the wing.
Diagnosis. A species with black thorax and legs entirely yellow apart from black front tibia and tarsi. The antennal stylus is exceptionally long and bare and the wing stigma very strongly marked. Male hypandrium with very long, narrow, apical process. Female sternite 8 with paired apical processes.
Description. Male: length 3.5–4.5 mm. Head subshining black; face vaguely yellowish below. Postocular setae black, several longish paler hairs on lower occiput. Antenna black, postpedicel ovate in lateral view, ~1.5– 2.0X long as wide; stylus long, ~8–10X long as postpedicel, black, bare, narrower on distal 0.2. Mouthparts blackish, palpus very narrow, with 1–2 distinct fine setae near tip. Thorax with ground colour black, postalar callus narrowly paler on outer edge; scutum subshining laterally but strongly dusted at extreme sides, with broad median brownish-grey dusted stripe, often slightly more shining in middle anteriorly; pleura dusted grey; acr fine but distinct, biserial; dc uniserial, small, fine but distinct; posterior dc long, strong; posterior acr no stronger than anterior ones; some fine hairs between anterior dc and postpronotal lobe; 1 npl, 1 pa and 2 sct distinct. Legs yellow with T 1 and anterior tarsi blackish; mid tarsomere 5 and extreme tip of F 1 and F 2 dusky. C 3 with fine black bristles anteroapically and laterally, coxae otherwise with pale hairs and bristles. F 1 with 1 fine long bristle ventrally at base and another posteroventrally at 0.2, otherwise short-haired. F 2 with av fringe of fine hairs longest basally; pv fringe with 1–2 longer dark bristles about middle; ad fringe short, with 1–2 slightly stronger hairs at ~0.6. F 3 distinctly inflated, widest 0.5 from base; viewed laterally upper and lower margins equally convex; ventral spines black, comprising single row of ~20 short spines becoming somewhat longer basally, in front of which are 8–10 longer bristles; pv fringe of 5–6 fine bristles on distal 0.6 slightly longer than limb is deep, contiguous with 4–5 shorter thicker bristles on proximal 0.4; 5–7 anterior proclinate bristles positioned evenly along length of limb stronger and distinct from surrounding finer setae. T 1 with 1 long pv bristle 0.3–0.4 from base 0.5X long as limb, otherwise with seta about as long as limb is deep but apical circlet with 1 pv conspicuously longer than others. T 2 with strong bristles dorsally at ~0.2 and 0.5 from base and ventrally at ~0.3 and 0.6 from base; apical circlet with 1 long pv bristle and 1 slightly shorter av. T 3 not inflated distally, slightly curved, with 4–5 erect dorsal setae somewhat longer than limb is deep and longer than surrounding setae. MT 1 with conspicuous av and pv ciliation of fine hairs, longest basally where 0.5X long as segment. MT 2 with 1 very short, yellow, ventrobasal bristle and longer dark hair dorsally near tip. MT 3 with short, fine, yellow hairs dorsally near base and tip. Wing membrane tinged brown, veins brown; stigma very distinct, blackish, short reaching costa at ~0.3–0.5 distance between end of R 1 and R 2+3. Costa faintly distorted about stigma such that anterior margin of wing slightly concave. Squamae with pale hairs. Halter white. Abdomen subshining brownish black, dusted grey; tergites with long pale bristles on posterior margin, becoming shorter on distal segments; sternites with longish hairs on disc and posterior margin, hardly shorter on distal segments. Terminalia (Figs 174–176) black with black setae; epandrial lamellae globoid; left surstylus elongate, broad throughout length, a small pointed dorsally projected basal lobe visible in lateral view (Fig. 176); right surstylus slightly broadened apically; hypandrium (Fig. 175) with long narrow apical process and dense ‘brush’ of dark bristles subapically. Female. Similar to male but MT 1 without conspicuous av and pv ciliation of fine hairs and F 3 slightly less evenly inflated, widest ~0.6 from base. Terminalia (Figs 177, 178) black, tergite 8 not encircling abdomen but with rounded, ventrally projected lateral lobes; sternite 8 hardly protuberant, with 2 long narrow apical processes, several long bristles on disc; sternite 10 weakly sclerotized.
Comment. Hybos stigmaticus sp. nov. is a distinctive species on account of its short strongly marked wing stigma and in having legs entirely yellow apart from the front tibia and tarsi. The form of the female terminalia in which sternite 8 has two narrow apical processes and of the male hypandrium which is greatly produced apically suggest a close relationship with H. ancistroides and perhaps also H. particularis. Hybos stigmaticus sp. nov. has been recorded from highly seasonal biotopes at low elevation (<180 m) during January and August in the south, February and July in the southeast and during November in extreme east of Thailand perhaps indicative of adult activity during the wet season (Figs 274, 300). The precise sites of capture at Phu Ha Kam and one of the Khao Kitchakut localities were areas of essentially dry evergreen forest with damp soils and rank vegetation adjacent to water courses.
description: Published as part of PLANT, ADRIAN R., 2013, The genus Hybos Meigen (Diptera: Empidoidea: Hybotidae) in Thailand, pp. 1-98 in Zootaxa 3690 (1) on pages 67-68, DOI: 10.11646/zootaxa.3690.1.1, http://zenodo.org/record/6329811