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

description: Hybos chaweewani sp. nov.
(Figs 35–37, 248, 287)
Type material. HOLOTYPE ♂: THAILAND, Nakhon Nayok Province, Khao Yai National Park, Nature trail in secondary moist evergreen forest, 14°24.515'N, 101°22.432'E, 750m, 5–12.viii.2006, Malaise trap, Pong Sandao [T400] (QSBG). PARATYPES: 2♀, same data as holotype; 2♂, 3♀, Nature trail in moist evergreen forest, 14°24.482'N, 101°22.388'E, 755 m, 5–12.viii.2006, 12–19.viii.2006; 3♂, 9♀, Nature trail in secondary forest, 14°24.522'N, 101°22.434'E, 750 m, 5–12.viii.2006, 12–19.viii.2006, 26.viii–2.ix.2006; 1♀, Cobra zone near Fire Protection Office, 14°28.524'N, 101°22.928'E, 757 m, 19–26.vi.2006; 1♀, evergreen forest near Tiger Trail, 14°27.511'N, 101°22.408'E, 760 m, 19–26.vi.2006; 2♀, Elephant Trail near Fire Protection Office, 14°28.285'N, 101°22.57'E, 751 m, pan trap, 9–10.vi.2007, 10–11.vi.2007; 2♂, 5♀, Nature trail in secondary moist evergreen forest, 14°24.515'N, 101°22.432'E, 750 m, 12–19.viii.2006: 1♂, Chanthaburi Province, Khao Khitchakut National Park, 500 m N/ Prabaht Unit, 12°48.98'N, 102°9.14'E, 12 m, 1–8.ix.2008 (QSBG, NMWC).
Additional material. 1♀, same data as holotype, evergreen forest near Tiger Trail, 14°27.511'N, 101°22.408'E, 760 m, 5–12.vi.2006: 1♂ Nakhon Nayok Province, Khao Yai National Park, Nature trail in secondary forest, 14°24.522'N, 101°22.434'E, 750 m, 26.viii–2.ix.2006 (damaged) (NMWC); 2♂ (anomalously setose specimens), 26.viii–2.ix.2006, 5–12.viii.2008 (QSBG): 1♂ (anomalously setose specimen), Elephant Trail near Fire Protection Office, 14°28.285'N, 101°22.57'E, 751 m, pan trap, 10–11.vi.2007 (NMWC).
Etymology. The species is named in honour of Chaweewan Hutacharern who has done much to foster taxonomy and conservation of invertebrates in Thailand.
Diagnosis. A yellow-legged species with clear yellow lower pleura and brownish black upper pleura and scutellum. The hind legs are usually rather slender in both sexes with two rows of ventral spines but setation of legs variable and some examples have more strongly setose legs and the male hind femur can be considerably inflated. The mid tibia usually lacks strong setae dorsally except for one very long bristle near the base (but sometimes a short but distinct bristle dorsally at 0.6–0.7) and below there are no strong bristles apart from one very long av at ~0.5. A strong ventral bristle at base of mid metatarsus but lacking a slightly smaller pv just distal to it. The male and female terminalia are characteristic.
Description. Male: body length 3.1–3.5 mm. Head subshining black, thinly dusted; face black above, yellowish on ventral 0.5. All setae dark; ocellars minute, upper postoculars somewhat curved anteriorly near tip. Antenna greyish black; postpedicel ovate in lateral view, 3.0 X long as wide, lacking dorsal seta; stylus bare, 4–5X long as postpedicel, apical 0.2 abruptly narrower, paler in certain lights. Mouthparts dark yellowish, palpus very narrow, with 1 distinct dark apical seta and a few smaller setae below. Thorax with scutum black, rather shining; thinly dusted but prescutellar area slightly stronger dusted; postalar callus yellowish. Katepisternum, meron and katatergite clear yellow; anepisternum, anepimeron, anatergite and mediotergite brownish black but anepimeron with posterior margin yellowish; scutellum dark, yellowish brown on disc (contrasting with katepisternum), posterior margin yellowish below. Acrostichals irregularly 4-serial, small, fine, widely spaced, posterior acr stronger; dc uniserial, similarly fine, posterior dc strong; a few fine hairs lateral to line of dc but prescutellar area bare; 1 strong (upper) and 1 weaker (lower) npl; 1 pa weak; scutellum with pair of strong black bristles and several fine marginal hairs. Legs yellow, tarsomeres 3–5 on all legs dark. Coxae with pale setae, longest on C 3, becoming darker anteroapically on all coxae. F 1 with pv fringe of fine setae as long as limb is deep near middle. F 2 with pv fringe of yellow hairs weak, a few longer hairs anteriorly near base, 1 blackish curved subapical ad bristle. F 3 not strongly inflated, widest ~0.8 from base, with rather long hairs, especially proximally; ventral spines black, comprising ~5–6 long bristles (as long or longer than limb is deep) immediately behind which are 9–12 much shorter spines; pv fringe strong, black on distal 0.3, becoming weaker and yellowish proximally; 2 (occasionally 3) distinct rather proclinate curving black bristles anteriorly at 0.6 and 0.95. T 1 with distinct erect dark seta dorsally at 0.6; rather long hairs ventrally; 1 strong black apical ad bristle.T 2 with strong black bristles 0.7 X long as limb dorsally at 0.2 and anteroventrally at 0.5 from base; otherwise with rather short setae, somewhat stronger dorsally, not becoming longer distally (sometimes 1 short dorsal bristle at ~0.6–0.7); apical circlet of 3–4 fine setae and 1 strong av 0.7X long as MT 2. T 3 slightly swollen apically where ~1.3X wide as at base; 1 small but distinct erect bristle dorsally at 0.5; 1 strong apical ad and 1 shorter anteroapical setae. MT 2 with strong erect bristle ventrally at base 0.5X long as segment. MT 3 short spinose ventrally. Wing membrane clear, very faintly tinged greyish; veins brown; stigma greyish, touching costa for complete distance between end of R 1 and R 2+3. Squamae with pale fringes. Halter white. Abdomen subshining black, paler ventrally near base; all setae pale. Terminalia (Figs 35–36) black but right surstylus and hypandrium distally yellowish. Epandrial lamellae rather quadrate in dorsal view (Fig. 35). Right surstylus large, widened distally, broadly trilobed. Left surstylus narrow, slightly incurved, 1 fine bristle subapically. Hypandrium (Fig. 36) narrow distally, with flattened bilobed apex bearing 2 long strong bristles; left margin concave, with row of strong erect bristles and elongate inner process. Female. Similar to male but ventral spines on F 3 rather longer. Terminalia (Fig. 37) with sternite 8 rounded in ventral view, anterior margin concave, partly hidden in lateral view by ventral part of tergite 8; sternite 10 small, brownish; tergite 10 very weakly sclerotized, hardly differentiated.
Comment. This species is most similar to Hybos tilokarati sp. nov. from which it can be distinguished by having dark (rather than yellowish) upper pleura and scutellum, hind femora with two more or less complete rows of ventral spines, distinct dorsal setae on front and hind tibiae, a strong ventrobasal seta on the mid metatarsus and very different male terminalia. Three male examples collected at the same locality as ‘typical’ specimens have anomalously strongly setose legs and quite closely resemble H. sinclairi sp. nov. Their terminalia appear to be identical with those of ‘typical’ examples but they are excluded from the type series. Whereas H. tilokarati sp. nov. and H. sinclairi sp. nov. are northern species in Thailand, so far as is known, H. chaweewani sp. nov. is restricted to lowland forests in central southern and south eastern regions of the country (Fig. 248), occurring in the Sankhampheng Mountains at Khao Yai and in the western extremity of the Cardamom Mountains along the border with Cambodia at Khao Khitchakut. Adults have been captured between June and early September, at the height of the wet season (Fig. 287).
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 21-22, DOI: 10.11646/zootaxa.3690.1.1, http://zenodo.org/record/6329811