Drapetis hutan, Grootaert & Shamshev, 2012

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 : 58-60

Drapetis hutan sp. nov.

Figs 94-97

Diagnosis

Small species; antenna brownish; palpus and proboscis brownish yellow; mid femur largely brownish yellow, hind femur dark brown; halter with brownish knob.

Description

Male LENGTH. Wing 1.4 mm.

HEAD. Black. Occiput subshining, finely pollinose. Two pairs of vertical bristles present (inner longer). Frons subshining, strongly broadened towards ocellar tubercle, very narrow above antennae, narrower than anterior ocellus.Anterior ocellars very short, inclinate; posterior ocellars long, lateroclinate.Antenna ( Fig. 94 ) brownish (postpedicel somewhat paler); pedicel with short lower seta; postpedicel with lower margin somewhat convex, 2.6 times longer than wide; stylus 2.5 times longer than postpedicel and 1.4 times longer than scape, pedicel and postpedicel combined. Gena very narrow. Palpus and proboscis brownish yellow.

THORAX. Black, with black setation. Prothoracic episternum with short setulae above fore coxa. Postpronotal bristle not prominent. Mesonotum with 2 notopleurals, 1 postsutural supra-alar, 1 postalar and 4 scutellars (inner pair very long, cruciate; outer pair very short); scutum entirely covered with short, pale uniform (except for 1 pair of long prescutellars) setulae.

LEGS. Short, with mid femur brownish yellow (except base) and hind femur brownish (except base), otherwise yellow. Mid coxa with several rather long and strong setae anteriorly; mid trochanter with 3 black spinules. Fore femur thickened. Fore tibia spindle-like. Mid femur with row of spinule-like ventral setulae and 1 long anterior subapical bristle. Hind femur evenly thickened, with 1 longer anteroventral subapical bristle. Hind tibia thickened, arched, with slightly prominent apical projection. Tarsi of all legs unmodified, with unmodified setation.

WING. Normally developed, hyaline, covered with uniform microtrichia. Costal vein with rather long setulae along anterior margin. Costal bristle long, brown. Costal index: 22/11/20. Vein Rs originating before middle of cell r 1 (closer to humeral crossvein), somewhat longer than crossvein bm-cu. R 1 thickened. R 2+3 evenly bowed toward costa, meeting costa beyond middle of wing. R 4+5 and M 1+2 strongly divergent, evenly bowed. A 1 absent. Crossvein bm-cu transverse. Crossvein r-m beyond middle of cell bm. Halter with pale stem and brownish knob.

ABDOMEN. Tergites 4 and 5 with squamiform setae laterally. Gland-like structure present between tergites 4 and 5.

TERMINALIA. Brown ( Figs 95-97 ). Cerci separated; left cercus broad, as in Fig. 102 , with numerous unmodified short setae; right cercus greatly reduced, represented as narrow, bacilliform sclerite bearing several short setulae. Epandrium completely divided. Left epandrial lamella fused to hypandrium, with 1 long seta apically. Left surstylus ( Fig. 97 ) bilobed; upper lobe long, digitiform, with internal process, bearing numerous unmodified setae; lower lobe short, with short unmodified setae. Right epandrial lamella subtriangular, covered with numerous unmodified long setae. Right surstylus deeply cleft as in Fig. 95 , with several unmodified setae of different lengths. Hypandrium with 1 short seta apically. Phallus short. Ejaculatory apodeme very large, ventral apodeme greatly reduced.

Female

Unknown.

Material examined

Holotype ♂

SINGAPORE: Nee Soon, 24 March 2005, swamp forest, Mal 1 (reg. 25028, leg. P.G.; in ZRC).

Etymology

The epithet 'hutan' means 'forest' in Bahasa Indonesia and Malaysia alluding to the occurrence of this species in the forest.

Distribution

Singapore.

Habitat and seasonal occurrence

This species was collected in a swamp forest in March.

Remarks

This species is similar to D. mandai sp. nov. and the main distinguishing features are indicated in the key.

Figures

Figs 94-97. Drapetis hutan sp. nov., ♂. 94. antenna, lateral view. 95. right surstylus, dorsal view. 96. epandrium and cerci. 97. left surstylus, lateral view.

Figs 101-104. Drapetis mandai sp. nov., ♂. 101. antenna, lateral view. 102. right surstylus, dorsal view. 103. epandrium and cerci. 104. left surstylus, lateral. Scale bar= 0.1 mm.