Hemerodromia fusca Yang & Yang

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: 31-32

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Hemerodromia fusca Yang & Yang


Hemerodromia fusca Yang & Yang 

( Figs 46, 47View FIGURES 46 – 47, 87View FIGURES 82 – 90)

Hemerodromia fusca Yang & Yang, 1986: 75  .

Diagnosis. A species with thorax black, legs and antennae variably blackish to yellowish. Front femur often darker. The male cercus is elongate in profile with a distinct dorsal process 0.5 from base. Surstylus extending beyond tip of epandrium, very conspicuously inflated apically where broadly T-shaped.

Re-description. Male: Body length 2.3 mm; wing length 2.0 mm. Head. Black, dusted brownish grey. Antenna sometimes entirely pale but often with scape and pedicel pale brown, postpedicel paler and stylus usually blackish. Mouthparts yellowish white with tip of proboscis brownish. 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 ~ 2 X long as wide, stylus rather shorter; scape with distinct fine dorsal seta. Thorax. Black, dusted greyish. All setae yellowish; minute apart from one npl; sct absent but scutellum with a pair of very small erect setulae on disc. Legs. Ground colour variably whitish yellow to dark blackish brown; often front legs (especially C 1 and/or F 1) darker than others, sometimes only C 1 dorsally darkened. C 1 ~ 1.2 X longer than distance between C 1 and C 2, all setulae minute except a few slightly longer dorsoapicals. C 2 and C 3 with a few fine setulae anteriorly. F 1 ~ 1.1–1.2 X long as C 1, ~ 4– 5 X long as wide, not at all constricted 0.3 from base; femoral formula ~ 7– 10 / 18–23 / 19–20 + 0–1 / 8–9, denticles black, rows converging apically; spines yellow, short, fine much shorter than limb is deep, longest basally, pv row somewhat longer than av row with basal spine of pv row longer still. T 1 ~ 0.7 X long as F 1, evenly curved, ventral face shallowly concave; with 2 rows of ~ 19 sharply pointed spinose setae ventrally; ventroapical spur hardly developed; a strong ventroapical erect black spinose seta present. Mid and hind legs slender with only small setulae. Wing. Membrane usually conspicuously darkened with black microtrichia but hyaline basally. Veins blackish but whitish near base. Marginal setulae greyish. R 2 + 3 linear, joining C ~ 0.7 X distance between end of R 1 and R 4; length of C between ends of R 2 + 3 and R 4 ~ 1.2–1.4 X long as R 4. R 4 almost linear, usually only slightly S-shaped, angle with R 5 at extreme base ~ 70–80 °, slightly swollen apically before junction with C; R 5 ~2.0– 2.2 X long as R 4; R 4 + 5 fork distal to M 1 + 2 fork by ~ 1.2–1.4 X length of R 4; R 5 and M 1 almost linear, convergent distally; cell bm+dm short, ending at level of R 1. Halter variably blackish, paler on stem; sometimes entirely dirty white. Abdomen. Black dusted greyish but tergite 1 and occasionally tergite 2 paler; sternite 1 paler on disc, sternite 2 whitish with dark median line and posterolateral marks; all setulae black, small except posteriorly and laterally on sternite 7. Terminalia. Black with dark setae. Cercus moderately elongate in lateral view, extending beyond tip of epandrium ( Fig. 46View FIGURES 46 – 47), a shorter dorsal lobe originating ~ 0.5 from base (sometimes twisted internally and inconspicuous in lateral view) ( Fig. 47View FIGURES 46 – 47). Epandrium ( Fig. 46View FIGURES 46 – 47) bluntly pointed ovoid, with strong setae distally. Hypandrium, with distinct setae posteroventrally. Surstylus present, extending beyond tip of epandrium, very conspicuously inflated apically where broadly T-shaped with close set minute black setulae in inner face dorsally. Elongate process with 2 hook-like modified setae apical, emerging just beyond tip of epandrium. Female: Similar to male but F 1 with basal spine of pv row much stronger, about as long as limb is deep. Abdomen with distinct setae on tergite 7 but all setae otherwise inconspicuous.

Material examined. 104 ♂, 102 ♀, Beung Kan, Chaiyaphum, Chantaburi, Chiang Mai, Kamphaeng Phet, Kanchanaburi, Khon Kaen, Lampang, Loei, Mukdahan, Nakhon Nayok, Nakhon Si Thammarat, Nan, Petchaburi and Surat Thani provinces ( QSBG, NMWC, INPA, MSU, MNHN). Note, 1 ♂, 1 ♀ removed for DNA sequence analysis ( INPA, MNHN); 24 specimens removed for population genetics studies ( MSU).

Remarks. This species is very similar to H. yunnanensis Yang & Yang, 1988  and also to H. phahompokensis  sp. nov. from which it differs primarily in morphology of the male terminalia (see discussion under H. yunnanensis  ). Hemerodromia fusca  was described from Fujian, China ( Yang & Yang 1986) but is also known from Yunnan ( Grootaert et al. 2000) so may be widely distributed across southern China. The author and J. T. Câmara (pers. comm.) have also seen specimens of this species in collections from Vietnam but precise collection localities are not available. In Thailand H. fusca  is present throughout the country ( Fig. 87View FIGURES 82 – 90), occurring in vicinity of streams and rivers in a variety of forest types and in irrigation channels in rice fields at 95–1,306 m. It has been taken in every month of the year but appears to be most abundant from September to March.


National Museum of Wales


Instituto Nacional de Pesquisas da Amazonia


Michigan State University Museum


Museum National d'Histoire Naturelle


Department of Natural Resources, Environment, The Arts and Sport














Hemerodromia fusca Yang & Yang

Plant, Adrian R. 2015

Hemerodromia fusca

Yang 1986: 75