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

description: Hybos grootaerti sp. nov.
(Figs 49–54, 251, 289)
Type material. HOLOTYPE ♂: THAILAND, Chiang Mai Province, Doi Phahompok National Park, Doi Phaluang, 20°1.06'N, 99°9.581'E, 1449 m, 21–28.iii.2008, Malaise trap, P.Wongchai [T6284] (QSBG). PARATYPES: 3♂, 7♀, same data as holotype; 4♂, 2♀, 28.iii.-7.iv.2008, 28.iv.-7.v.2008; 16♂, 14♀, Doi Phahompok National Park, Kiewlom 1/montane forest, 20°3.549'N, 99°8.552'E, 2174 m, 14–21.iii.2008, 21– 28.iii.2008, 28.iii.-7.iv.2008, 7–14.iv.2008, 14–21.iv.2008, 28.iv.-7.v.2008 (QSBG and NMWC).
Additional material. 3♂, 4♀, Doi Phahompok National Park, Kiewlom 1/montane forest, 20°3.549'N, 99°8.552'E, 2174 m, 14–21.iii.2008 (QSBG).
Etymology. The species is named in honour of Patrick Grootaert, a dedicated student of Hybotidae.
Diagnosis. A black legged species with entirely pale setae on coxae and posterior femur inflated, not at all petiolate basally. The antennal stylus is subplumose basally but with apical half bare. The mid tibia lacks a strong ventral bristle and has two dorsals only 0.2X length of limb and the mid metatarsus lacks a strong ventral bristle at base. The hind tibia is equally wide throughout its length and not swollen apically. In males the front metatarsus is strongly ciliated anteriorly and posteriorly with fine long hairs.
Description. Male: body length 2.5–3.0 mm. Head subshining black, dusted silvery greyish, face yellowish, often narrowly blackish at eye margin; occipital setae black, paler hairs on lower occiput. Antenna brownish black; postpedicel ovate in lateral view, ~1.5X long as wide, lacking dorsal setae; stylus 4–6X long as postpedicel, black, thickened and subplumose on proximal 0.5–0.6, apical 0.4–0.5 bare. Mouthparts blackish, palpus narrow, with sparse row of fine hairs laterally becoming 3–4X long as palp is wide distally. Thorax with ground colour black, yellowish laterally behind wing; rather thickly dusted silvery grey; scutum with indications of stronger pollinose stripe along line of dc in some lights; acr irregularly biserial becoming 4-serial about middle, distinct, fine and hairlike, about as long as anterior dc throughout (posterior acr not longer than others); dc uniserial but posterior dc before prescutellar area longer, as long as upper npl and sct but shorter than pa. Legs subshining black, thinly dusted greyish, coxae more strongly dusted; tarsi sometimes faintly yellowish, especially on mid leg; ‘knees’ of front and mid legs often brownish yellow but basal geniculation of T 3 clearly and sharply demarked clear yellow. Coxae with hairs and bristles white, at most a few dark hairs anteroapically. F 1 slightly swollen on basal 0.5, ventral fringe of pale hairs almost as long as limb is deep. F 2 not narrowed on basal 0.5 viewed from above; av and pv fringes of pale hairs strong, ~3X long as limb is wide, no distinct anterior fringe of hairs basally. F 3 strongly inflated, widest 0.5–0.7 from base, dorsal margin convex, ventral margin about linear in profile; rather evenly covered with fine pale pubescent hairs; ventral armature consisting of ~10 evenly sized strong black av spines, ventral series or more numerous smaller spines behind which on basal 0.3 are 4–5 stronger spines; pv fringe yellowish, hairs as long as limb is wide on distal 0.3, becoming shorter basally where merging with general pubescence; distinct black ad bristles at 0.6 and 0.8. T 1 with ventral fringe of pale hairs erect, becoming 3X long as limb is deep distally; dorsal fringe darker, rather proclinate with short but distinct black bristles at 0.15, 0.5 (and sometimes 0.7) from base; apical circlet strong. T 2 with strong bristles 0.2–0.3 X long as limb dorsally at 0.15 and 0.45; apical circlet with only weak dorsal setae but with very strong av and somewhat weaker pv bristles. T 3 not at all petiolate basally; dorsal hairs no longer than limb is deep, but 1 preapical 2–3X long, erect; patch of short erect pile posteroapically contiguous with similar pile on MT 3. Front tarsus with long hairs anteriorly and posteriorly on MT 1, almost as long as segment, shorter on second tarsomere. MT 2 without strong seta near base. MT3 with distinct ventral spine-like setae. Wing membrane clear or faintly darkened distal to basal cells; veins yellowish brown; stigma distinct, brown, short, reaching costa 0.6–0.7 distance between end of R 1 and R 2+3. Squamae with pale fringes. Halter white, base of stem darker. Abdomen with tergites subshining black, thinly dusted, sternites paler, more shining; all setae white (including those on terminalia), longest and more numerous laterally on proximal tergites. Terminalia (Figs 49–52) with left epandrial lamella (Fig. 50) broad, inner margin sublinear; left surstylus triangular; right epandrial lamella (Fig. 51) elongate, rather narrow. Right surstylus with two narrow digitiform lobes curving inwardly; upper lobe rather strongly curved; lower lobe much longer, less strongly curved, narrowed basally. Hypandrium (Fig. 52) broad, with two broad apical lobes on inner face and regular series of uniformly sized strong bristles subapically. Female. Similar to male but F 3 slightly more slender with ad bristles at 0.6 and 0.8 weaker and somewhat yellowish. MT 1 without long hairs anteriorly and posteriorly. F 2 with av and pv fringes of pale hairs rather weaker. Terminalia (Figs 53, 54) with tergite 8 more strongly sclerotized and narrowed basally than apically (narrowed part often hidden beneath preceding sternite), with distinct erect bristles especially on slightly inflated area immediately distal to narrowed area. Sternite 10 almost quadrate in ventral view (Fig. 53).
Comment. Hybos grootaerti sp. nov. may be distinguished from other Thailand Hybos with a subplumose stylus, postpedicel lacking dorsal setae and coxae with pale hairs by the lack of a strong ventral bristle on the mid tibia. Damaged specimens of H. thepkaisoni sp. nov. H. tetricus sp. nov. or H. hylobates sp. nov. might be confused with H. grootaerti sp. nov. if they have lost this ventral bristle, but in these three species the two dorsal bristles on the mid tibia are much stronger than in H. grootaerti sp. nov. and the stylus is more extensively subplumose. Hybos grootaerti sp. nov. is only known from hill evergreen and moist hill evergreen forest at 1,449 – 2,174 m in mountains of the Daen Lao Range along the border with Burma in the north of Thailand at Doi Phahompok (Fig. 251). Adults were captured between mid March and early May (Fig. 289), coincident with the end of the cool dry season and start of the wet season.
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 26-27, DOI: 10.11646/zootaxa.3690.1.1, http://zenodo.org/record/6329811