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

description: Hybos anisoserratus sp. nov.
(Figs 22–25, 245, 285)
Type material. HOLOTYPE ♂: THAILAND Nan Province, Doi Phu Kha National Park, Office 4, 19°12.562'N, 101°4.93'E, 1374 m, 8–15.ix.2007, Malaise trap, Charoen & Nikom [T3212] (QSBG). PARATYPES: 2♂, 12♀, same data as holotype, 8–15.ix.2007, 1–8.ix.2007, 15–22.ix.2007; 1♂, 1♀, Office 3, 19°12.326'N, 101°4.765'E, 1332 m, 22–29.viii.2007; 1♀, Office 10, 19°12.557'N, 101°5.041'E, 1380 m, 1–8.xi.2007; 1♀, Office 8, 19°12.439'N, 101°4.825'E, 1358 m, 1–8.x.2007, 22–29.x.2007; 1♀, Office 15, 19°12.133'N, 101°4.756'E, 1310 m, 1–8.xii.2007; 2♀, Office 13, 19°12.605'N, 101°5.074'E, 1371 m, 15–22.xii.2007; 1♂, 2♀, Office 9, 19°12.252'N, 101°4.697'E, 1350 m, 15–22.x.2007; 2♀, Office 12, 19°12.138'N, 101°4.711'E, 1331 m, 8–15.xi.2007; 1♂, 2♀, Office 11, 19°12.458'N, 101°4.866'E, 1359 m, 8–15.xi.2007, 15–22.xi.2007: 8♂, 3♀, Loei Province, Phu Ruea National Park, Hua Dong Tamsun, 17°29.54'N, 101°20.995'E, 1130 m, 19–26.v.2007, 26.v.-2.vi.2007 (QSBG and NMWC).
Etymology. The prefix aniso (not equal to) is attached to serratus to indicate that although superficially similar to H. serratus, it is not the same species.
Diagnosis. A yellow legged species with only the tip of hind femur and base of hind tibia blackish. The antennal stylus is distinctly subplumose with a bare tip. Both left and right surstyli are narrowly elongate and the hypandrium narrowed distally with apical digitiform process and a shorter blunter rather yellowish process emerging internally. In females, tergite 8 does not encircle the abdomen and sternite 8 is rather weakly sclerotized laterally.
Description. Male: length 2.6–3.4 mm. Head subshining black; face dark blackish yellow below. Postocular setae black, a few paler hairs on lower occiput. Antenna black, postpedicel ovate in lateral view, ~2.5 X long as wide; stylus ~5X long as postpedicel, black and distinctly subplumose on basal 0.8, bare on distal 0.2. Mouthparts blackish, palpus very narrow, with fine setae apically and ventrally near middle. Thorax with ground colour black, postalar callus, scutellum basally and pleura somewhat paler; pleura and scutum (especially about prescutellar area); pollinose; acr biserial, dc uniserial, small, fine but distinct; posterior dc and acr, upper npl (2X long as lower npl), pa and 2 sct distinct, other setae small, hair-like. Legs mostly yellow with F 3 on apical 0.1 blackish; T 3 variably darker on basal 0.3, clear yellow distally; T 1 entirely yellow (occasionally very vaguely darkened), not darker than T 2; all tarsi yellow, becoming slightly darker on distal segments. Coxae with pale hairs and bristles. F 1 with erect pv hairs not longer than limb is deep. F 2 very slightly distorted, weakly concave in front about 0.3 from base where ad series of fine bristles almost as long as limb is deep. F 3 moderately inflated, widest 0.6–0.7 from base; viewed laterally upper margin convex, lower margin almost linear; ventral spines black, rather variable in number and arrangement, usually comprising 7–9 strong bristles (some of which on proximal 0.8 are slightly longer than limb is deep) behind which are ~12–17 mostly shorter, more evenly sized bristles, sometimes with a few extra bristles distributed between or posterior to the two main series; pv fringe with ~3 strong black bristles on distal 0.3, otherwise weakly developed and yellowish; 4–5 rather proclinate distinct curved black anterior proclinate bristles on distal 0.5. T 1 with fine but distinct hair dorsally at 0.6 and 1 somewhat longer seta anteroapically in apical circlet, otherwise short-haired.T 2 with strong bristles dorsally at ~0.2 and ~0.4–0.5 from base and 1 rather longer bristle ventrally at ~0.5; apical circlet with 1 av bristle much longer than others. T 3 somewhat inflated distally, ~1.5–1.8X wide at tip than at base; 1 strong bristle dorsally ~0.5–0.6 from base; apical circlet with 3 distinct bristles. MT 1 and MT 2 with distinct ventrobasal bristle. MT 2 with distinct ventral bristles medially and at tip. Wing membrane tinged brown, veins brown; stigma distinct, reaching costa at ~0.9 distance between end of R 1 and R 2+3. Squamae with pale hairs. Halter white. Abdomen subshining brownish black, tergites with long pale to blackish bristles on posterior margin, becoming shorter on distal segments. Sternites with long hairs on disc, hardly shorter on distal segments. Terminalia (Figs 22–24) black, with black setae; left epandrial lamella (Fig. 24) almost trapezoid with two apical processes and long apical bristles; left surstylus elongate, slightly broadened apically; right epandrial lamella subspherical with right surstylus elongate, directed internally (Fig. 22); hypandrium (Fig. 23) rather broad, narrowed distally with apical digitiform process and shorter blunter rather yellowish process emerging internally. Female: Similar to male but F 3 much less strongly inflated, widest ~0.8–0.9 from base; ventral spines comprising ~9 distinct bristles arranged in a single row; pv fringe weaker; usually only 1–2 distinct anterior proclinate bristlesand a few longish hairs near tip. Abdomal tergites with longish hairs posteriorly on segments 1–3, shorter on distal segments; tergites with sparser long hairs on disc. Terminalia (Fig. 25) black, tergite 8 not encircling abdomen; sternite 8 slightly protuberant, rather variably sclerotized but with blackish median area becoming broader basally, laterally paler; when viewed ventrally usually with somewhat darker posterior margin.
Comment. Hybos anisoserratus sp. nov. is most likely to be confused with H. serratus Yang & Yang, 1992. Hybos anisoserratus sp. nov. however is smaller and usually has more extensively yellow legs than that species. In particular, the front tibia is at most very faintly darkened and obviously no darker than the mid tibia, the hind tibia is extensively clear yellow, becoming darker only near its base. In H. serratus the hind tibia varies from more or less entirely clear yellow to diffusely blackish yellow when dark colouration occurs near the tip as well as basally. In H. anisoserratus sp. nov. the basal segments of the posterior tarsus are yellow whereas in H. serratus they are often (but not always) considerably darkened. The hind femora is somewhat more spinose ventrally in males of H. anisoserratus sp. nov. and there is a tendency for there to be three rather than two rows as in H. serratus although the number and position of the larger bristles varies somewhat in both species. The terminalia of both males and females of the two species are very distinctive and afford numerous differential characters.
Hybos anisoserratus sp. nov. is known only from elevations between 1,100 m and 1,400 m on mountains along the border between Thailand and Laos in the Luang Prabang Range in Nan Province and the Petchabun Range in Loei Province (Fig. 245). Adults occur mostly from September to December and again in May and early June consistent with emergent activity at the start and end of the wet season (Fig. 285).
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 16-17, DOI: 10.11646/zootaxa.3690.1.1, http://zenodo.org/record/6329811