Hemerodromia phahompokensis, Plant, Adrian R., 2015

Plant, Adrian R., 2015, Diversity of Hemerodromia Meigen, 1822 (Diptera: Empididae) in Thailand, the tip of a tropical iceberg?, Zootaxa 4039 (1), pp. 1-56 : 40

Hemerodromia phahompokensis sp. nov.

( Figs 60–62 , 93 )

Diagnosis. A black species, slightly tinged reddish with basal sternites contrastingly yellow. The male cercus is very elongate in profile and in dorsal view. Surstylus with two elongate processes projecting beyond tip of epandrium; upper one narrow, apically spatulate with minute peg-like tubercles apically on inner face; lower one digitiform, with dense brush of fine coalescent hairs apically.

Description. Male: Body length 2.2 mm; wing length 1.9 mm. Head. Black, dusted greyish. Antenna and mouthparts pale whitish yellow. One pair reclinate ocl; two pairs small vtl distinguishable from smaller fine hairs on vertex and upper occiput; postocular and lower occipital setulae minute. Antenna with postpedicel ~1.8X long as wide, stylus slightly shorter; scape with distinct fine dorsal seta. Thorax. Ground colour black, slightly tinted dark reddish especially on pleura and postpronotal are, dusted greyish. All setae yellowish; minute apart from one small npl; a pair of very small sct. Legs. Ground colour yellow including apical tarsomeres. C1 ~1.1–1.2X longer than distance between C1 and C2; all coxae with only minute setulae. F1 ~1.1X long as C1, moderately inflated ~ 5X long as wide, hardly constricted at 0.25 from base; femoral formula ~ 6/15/16 +1/5; denticles black, rows converging apically, pv spines slightly longer than av series, both becoming longer proximally. T1 ~ 0.6–0.7X long as F1, evenly curved, ventral face shallowly concave; with one row of ~15 sharply pointed spinose setae ventrally; ventroapical spur weakly developed, a strong ventroapical erect black spinose seta arising from near its base. Mid and hind legs slender with only small setulae. Wing. Membrane usually slightly but distinctly darkened with greyish microtrichia but hyaline near extreme base. Veins brownish grey but paler near base. Marginal setulae brownish. R2+3 linear, joining C ~ 0.7X distance between end of R1 and R4; length of C between ends of R2+3 and R4 ~1.5X long as R4. R4 almost linear, only slightly S-shaped, angle with R5 at extreme base ~ 70°; R5 ~ 2X long as R4; R4+5 fork distal to M1+2 fork by ~ 1.0X length of R4; R5 and M1 almost linear, somewhat convergent becoming slightly divergent distally; cell bm+dm rather long, ending at slightly beyond level of R1. Halter with knob brownish black, stem paler. Abdomen. Ground colour black, slightly tinted dark reddish, dusted greyish but sternites 1 and base of sternites 2 contrastingly dirty yellow; all setulae pale, small, slightly stronger on sternites than on tergites. Terminalia. Black with dark setae. Cercus very elongate in lateral view ( Fig. 60 ), extending well beyond tip of epandrium, bearing numerous distinct setae; in dorsal view ( Fig. 61 ) distal lobe narrow, almost linear, slightly curved inwards near tip; basal lobe short, with small triangular process on inner posterior margin. Epandrium small, subcircular in lateral view, with a few distinct setae. Surstylus with two elongate processes projecting beyond tip of epandrium; upper one narrow, apically spatulate with minute peg-like tubercles apically on inner face ( Fig. 62 ); lower one rather digitiform, with dense brush of fine almost coalescent hairs apically. Hypandrium rather strongly arched ventrally, distinctly divided ventrally near base. Female: Similar to male but basal spines on F1 and apical bristle on T1 rather stronger; femoral formula ~ 6/15/19 +1/5. Abdomen with sternites whitish but with sternite 7 entirely and sternite 1 along posterior margin blackish; sternite 6 with 4 minute circular dark marks medially at base and irregularly darkened near posterior margin.

Type material. HOLOTYPE ♂, THAILAND: Chiang Mai Province, Doi Phahompok NP, Doi Phaluang, 1,449 m, 20°1.06'N 99°9.581'E, 7–14.x.2007, P.Wongchai, [T6186]( QSBG). PARATYPES: 1♀, same data as holotype; 1♀, 28.xi.2007 ( QSBG).

Etymology. The specific epithet refers to the mountain Doi Phahompok in northern Thailand which is the only known locality for this species.

Remarks. Hemerodromia phahompokensis sp. nov. is similar to many other Oriental Hemerodromia having a black thorax, pale legs and fork M1+2 present. The species might readily be confused with H. fusca Yang & Yang, 1986 or H. yunnanensis Yang & Yang, 1988 from which it differs by the shape of the cercus and of the two processes of the surstylus projecting beyond the tip of the epandrium (see discussion under H. yunnanensis ). The species is known from hill evergreen forest on the mountain Doi Phahompok in Chiang Mai Province, northern Thailand ( Fig. 93 ), during October and November (during the cool dry season)

Figures

FIGURES 60 – 62. Male terminalia of Hemerodromia phahompokensis sp. nov. 60, lateral view of terminalia; 61, dorsal view of cerci; 62, apex of upper lobe of surstylus (inner face). Abbreviations: cer = cerci, epa = epandrium, hyp = hypandrium, lsur = lower lobe of surstylus, usur = upper lobe of surstylus.

FIGURES 91 – 98. Distribution of Hemerodromia spp. in Thailand at a resolution of 0.25 ° of latitude and longitude with symbols scaled to 0.5 °. 91, H. ocellata sp. nov.; 92, H. oriens sp. nov.; 93, H. phahompokensis sp. nov.; 94, H. songsee sp. nov.; 95, H. systoechon sp. nov.; 96, H. yunnanensis Yang & Yang; 97, H. zetalutea sp. nov.; 98, Species richness of Hemerodromia spp. in Thailand at a resolution of 1 ° with symbols plotted at same resolution.