Hybos xishuangbannaensis Yang & Yang
Creators: name: PLANT, ADRIAN R.
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Hybotidae
Hybos
Hybos xishuangbannaensis

description: Hybos xishuangbannaensis Yang & Yang
(Figs 207–213, 280, 305)
Hybos xishuangbannaensis Yang & Yang, 2004: 225.
Material examined. 4♂, THAILAND, Chaiyaphum Province, Pa Hin Ngam National Park, Ecotone between mix deciduous/dry dipterocarp, 15°38.132'N, 101°23.922'E, 698 m, 11–12.viii.2006, 18–24.viii.2006, 24–30.viii.2006; 1♀, Tung Dok Grajeaw, 15°38.208'N, 101°23.556'E, 720 m, 19–24.vii.2006; 3♀, creek at Tung Dok Grajeaw, 15°38.391'N, 101°23.609'E, 750 m, 19–24.vii.2006; 2♂. 1♀, Dry dipterocarp, 15°38.099'N, 101°23.921'E, 698 m, 18–24.viii.2008: 2♂, 2♀, Nakhon Nayok Province, Khao Yai National Park, behind football field, 14°24.619'N, 101°22.778'E, 770 m, 26.vii.-2.viii.2006: 1♂, Sakon Nakhon Province, Phu Pha Yon National Park, Channel, 16°55.639'N, 104°10.748'E, 295 m, 23–29.vii.2006: 1♀, Petchaburi Province, Kaeng Krachan National Park, Panernthung /km27/water pump, 12°49.151'N, 99°22.483'E, 970 m, 5–12.ix.2008: 1♀, Suphanburi Province, Pu Toei National Park, Pinus merkusii forest, 14°58.4'N, 99°26.017'E, 763 m, 8–15.vii.2008: 1♀, Chiang Mai Province, Doi Inthanon National Park, Vachiratharn Falls, 18°32.311'N, 98°36.048'E, 700 m, 8–15.vii.2006; 1♂, Doi Phahompok National Park, Mae Fang Hotspring, 19°57.961'N, 99°9.355'E, 569 m, 28.ix.-4.x.2007; 2♂, Doi Chiang Dao, HRD Pakea Station, 19°18'50.7''N, 98°49'57.8''E, 1560 m, 3.vii–5.viii.2009, 4.ix–10.ix.2009; 2♂, Queen Sirikit Botanic Garden, semi-evergreen forest, 18°54'14.6''N, 98°51'41.8''E, 727 m, 16–23.vi.2009, 23– 30.vi.2009 (QSBG and NMWC).
Diagnosis. A black legged species with antennal stylus bare, black setae behind hind coxa and hind femur strongly inflated, not at all petiolate basally. The mid femur is somewhat distorted with a slight concavity in front 0.3–0.4 from base and there is a strong ventral bristle at base of mid metatarsus. Separated from Hybos daugeroni sp. nov. by having the mid tibia with 2 strong and 1 weaker dorsal bristles; hypandrium apically narrow and decurved and female sternite 8 moderately enlarged and rounded in profile with distinct black bristles projecting posteroventrally.
Description. Male: body length 3.5–5.0 mm. Head subshining black, dusted greyish; face slightly paler reddish black, small patch posterolateral to mouth edge more strongly dusted, clypeus shining; occipital setae black. Antenna black; with postpedicel ovate in lateral view, 2X long as wide, bearing 1 distinct fine dorsal seta; stylus bare, 5–6X long as postpedicel, vaguely paler apically. Mouthparts blackish, palpus very narrow, fine hairs below not obviously longer than those at tip. Thorax with ground colour black; postalar callus anterolaterally, outer face of postpronotal lobe and small patch in front of root of halter narrowly yellowish; dusted greyish on pleura, slightly more yellowish grey on scutum and scutellum; vague indications of darker yellowish grey dust stripes on scutum anteriorly along line of dc; acr irregularly 4-serial, hair-like, but posterior bristle of outer series stronger; dc uniserial, hair-like, but posterior bristle strong; 1 strong and 1 weak npl; pa moderately strong with several smaller hairs adjacent; scutellum with 2 distinct sct and about 8 fine marginal hairs. Legs subshining black but yellowish on T 3 about geniculation at extreme base and F 3 anteroapically at extreme apex; dusted greyish. Coxae with setae mostly dark and hair-like; rather sparse (including C 3 posteriorly) but stronger and bristle-like distally on outer face of C 3. F 1 with evenly spaced row of fine dark hairs below becoming shorter distally; 2–3 short dorsal preapical bristles. F 2 slightly twisted and distorted, weakly concave in front about 0.3–0.4 from base where ad series of fine bristles almost as long as limb is deep; pv hairs longest on basal 0.6 where blackish and as long as limb is deep. F 3 strongly and quite evenly inflated, widest 0.5–0.6 from base, rather evenly but sparsely covered with short hairs which are rather longer behind almost merging with pv series of conspicuous fine hairs which are as long as limb is deep 0.7–0.9 from base; ventral row of about 16 short spines adjacent to which is a short series of 4 slightly longer pv bristles on basal 0.3 and a complete series of 8–9 av bristles which are almost as long as limb is deep; 1 small ad bristle 0.7 from base and 1 stronger at 0.9; 2–3 fine dorsoapical hairs. T 1 with 3 fine dorsal bristles more or less distinguished from more numerous dorsal hairs; 1 series of more numerous somewhat longer fine hairs ventrally; 4–5 distinct apical setae with ad longest; av pile short, inconspicuous, yellowish. T 2 slender with 2 strong equally sized dorsal bristles 0.4X long as limb at 0.15 and 0.4 from base and often another slightly shorter at 0.6; strong av bristles 0.3–0.4X long as limb at 0.6 and apically and another shorter bristle at 0.4; 2–3 shorter apical setae. T 3 with only short hairs, lacking distinct bristles; posteroapical patch of yellowish pile. MT 1 with longish fine hairs below. MT 2 with 1 very strong ventral bristle at base, almost as long as segment. MT 3 short pilose, with several very short spine-like setae ventrally and yellowish pile behind. Wing membrane clear; veins brownish, becoming yellowish basally; stigma faint, brownish, long, reaching costa 0.7–0.8 distance between end of R 1 and R 2+3. Squamae with pale fringes. Halter yellowish white, stem darker. Abdomen black, strongly dusted greyish brown, less shining than thorax; bristly hairs pale, longest and more numerous laterally. Terminalia (Figs 207–211) with long black distinctly crinkled bristles. Left epandrial lamella rounded in profile with inner margin concave. Left surstylus (Figs 209, 210) short, quadrate in profile with short upturned apical ‘beak’. Right epandrial lamella rounded with inner margin concave. Right surstylus (Fig. 211) very short. Hypandrium (Fig. 208) distally narrowed, apical decurved, lacking strong setae. Female. Similar to male but pubescence on F 3 slightly longer, especially behind. Abdominal dusting less strong and distinctly greyish; tergites 7 and 8 paler, often yellowish brown; segment 10 yellow, weakly sclerotized. Terminalia (Figs 212, 213) with sternite 8 moderately enlarged, rounded in profile, with distinct black bristles projecting posteroventrally.
Comments. Hybos xishuangbannaensis is rather variable in size and there are small differences in the shape of the hypandrium between populations from different regions of Thailand. However, I do not consider any of these differences significant enough to warrant their description as new taxa. In Thailand the species might be confused with H. longus Yang & Yang, 2004, H. meeamnat sp. nov., H. paknok sp. nov. and especially H. daugeroni sp. nov. and differences are discussed in the species accounts of these taxa. Originally described from southern Yunnan, China, H. xishuangbannaensis is widely distributed in Thailand occurring in the Daen Lao and Thanon Thongchai ranges of the north as far south as Kaeng Krachan in the Tenasserim Hills (Fig. 280). In the east it is found in the Dong Paya Yen—Khao Yai forest complex along the western margins of the Isaan Plateau and in the Phu Pan Range. It is largely confined to seasonally arid forests at low elevation (<800 m). Adults are active between June and early October (with peak abundance in July) during the wet season (Fig. 305).
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 78-80, DOI: 10.11646/zootaxa.3690.1.1, http://zenodo.org/record/6329811