Elaphropeza semakau

Grootaert, Patrick & Shamshev, Igor V., 2012, The fast-running flies (Diptera, Hybotidae, Tachydromiinae) of Singapore and adjacent regions, European Journal of Taxonomy 5, pp. 1-162: 103-106

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Elaphropeza semakau

sp. nov.

Elaphropeza semakau  sp. nov.

Figs 156-160View Figs 156-160


Occiput black; postpedicel brownish in apical part and yellow basally, nearly 3.5 times longer than wide; thorax with scutellum and metanotum brown; legs with tarsomere 5 black, hind tibia with 1 anterodorsal bristle. Male: cerci entirely fused, left surstylus produced apically, right epandrial lamella bearing 4 short subapical spine-like setae.


Male LENGTH. Body 1.9 mm, wing 1.7 mm.

HEAD. Occiput black. Anterior ocellars long, proclinate and cruciate; posterior ocellars minute. Inner verticals long, outer verticals somewhat shorter. Antenna ( Fig. 156View Figs 156-160) with scape and pedicel yellow, postpedicel brownish in apical part and yellowish basally (yellow space varying, but no more than half of postpedicel); pedicel with circlet of subequally short setulae; postpedicel 3.7 times longer than wide; stylus normally pubescent, brown, slightly (1.2 times) longer than postpedicel and slightly shorter (1.1 times) than scape, pedicel and postpedicel combined. Palpus yellow, small, rounded.

THORAX. Almost entirely yellow, only scutellum and metanotum brown. Prothoracic episternum lacking long upturned bristle just above fore coxa, with 1 very short bristle in upper part. Postpronotal bristle not prominent. Mesonotum with 2 subequally long notopleurals, 1 somewhat shorter postsutural supra-alar, 1 similar postalar and 4 scutellars (apical pair very long, cruciate; lateral pair minute).Acrostichals arranged in 4 irregular rows anteriorly but 2-serial posteriorly, lacking on prescutellar depression; dorsocentrals arranged in 2-3 irregular rows anteriorly, becoming uni-serial toward scutellum, prescutellar pair very long (nearly as long as apical scutellars).

LEGS. Almost entirely yellow, only tarsomere 5 of all legs black. Coxae and trochanters with unmodified setation. Fore femur somewhat thickened, with rows of short anteroventral and posteroventral bristles, 2 longer pale setae near base and 1 strong brownish subapical bristle posteriorly. Fore tibia lacking prominent bristles (except subapicals). Mid femur with rows of spinule-like, short ventral setae. Mid tibia with slightly prominent ventral spinules, bearing subapical, black claw-like spine, lacking prominent bristles (except subapicals). Hind femur with row of short anteroventral setae and about 4 short, erect dorsal setae near base. Hind tibia bearing 1 anterodorsal bristle, with slightly prominent rounded apical projection. Tarsi of all legs unmodified.

WING. Uniformly finely infuscate. Costal index: 34/22/24/12. Costal vein with moderately long setulae along anterior margin. Basal costal bristle long, brownish yellow. R 4+5 and M 1+2 somewhat divergent near wing apex, both straight. Crossvein bm-cu transverse. Crossvein r-m near middle of cell bm. Calypter brownish yellow, with several long concolorous setae. Halter pale yellow.

ABDOMEN. Tergite 1 entirely pale yellow. Tergites 2 and 3 brownish yellow, of subequal width in dorsal view, deeply concave anteriorly and divided along midline; with unmodified setation. Tergite 4 broadest, dark brown, subshining, with slightly flattened setae. Tergite 5 very narrow, concolorous with tergite 4, bearing squamiform setae. Tergites 6 and 7 brownish yellow, with moderately long posteromarginal setae.

TERMINALIA. Rather large, left surstylus brownish, right epandrial lamella yellowish brown apically and yellow basally ( Figs 157-160View Figs 156-160). Cerci entirely fused forming single subrectangular lobe, with some unmodified setae of different lengths, lacking spines. Epandrium completely divided. Right surstylus not prominent. Right epandrial lamella ( Fig. 157View Figs 156-160) conical, broadly ovate apically, bearing 4 short, subapical spine-like setae (3 setae closer to each other and 1 seta aside), with numerous moderately long setae. Left epandrial lamella fused to hypandrium, with 1 short seta apically. Left surstylus ( Fig. 159View Figs 156-160) with upper lobe large, rather elongate oval and narrowly produced apical part, covered with scattered setulae on outer face but bearing some moderately long setae on inner face and several short strong setae near base dorsally. Hypandrium with 2 long subapical setae and numerous setae of different lengths apically ( Fig. 160View Figs 156-160). Phallus short. Two rod-shaped apodemes present.



Material examined

Holotype ♂ SINGAPORE: 1 ♂, Semakau (SMK01), 27 May 2009, mangrove, Mal. (reg. 29115, leg. P.G.; in ZRC). 


The species is named after Semakau Island that appears to have a very rich empidoid fauna (Grootaert, in litt.).



Habitat and seasonal occurrence

This species occurs in mangroves, with a single record from May.


The new species is very similar to E. feminata  differing from the latter only by the body size and the structure of the male terminalia. Elaphropeza semakau  sp. nov. is smaller (1.9 mm vs. 2.4-2.5 mm in E. feminata  ) and in the new species the left surstylus is apically produced (with shallow notch in E. feminata  ), right epandrial lamella bears 4 short subapical spine-like setae, cerci are entirely fused forming single subrectangular lobe and, additionally, the apex of the hypandrium is covered with numerous spine-like setae. The females of E. feminata  have modified abdominal segment 8 that may aid distinguish them from the females of E. semakau  sp. nov. once they are collected.