Tachydromia tigeri, Shamshev, Igor & Grootaert, Patrick, 2008

Shamshev, Igor & Grootaert, Patrick, 2008, New and little-known species of the genus Tachydromia Meigen (Diptera, Hybotidae) from Thailand, Zootaxa 1830, pp. 21-36 : 27-29

Tachydromia tigeri sp. nov.

( Figs 7–9 , 26 )

Diagnosis. Postpedicel brownish. Palpus brownish yellow. Legs with complicated colour pattern: largely finely brownish infuscate, with large brown patch on subapical part. Halter with brown knob. Male: fore tibia mostly bare posteriorly but with rather long curved thin setae along sides of bare space.

Description. Male. Wing 2.9–3.0 mm. Head black in ground-colour. Eyes extending beyond ocellar tubercle. Frons subshining, slightly widened toward ocellar tubercle, above antennae nearly 1.5 times as broad as anterior ocellus. Ocellars minute. Occiput largely shining, narrowly pollinose behind eyes; with 2 moderately long strong black cruciate setae in upper part, 2 similar setae on middle part laterally and numerous pale hair-like setae near neck and on lower part. Basal antennal segments yellow; postpedicel and stylus brownish; postpedicel about 2.5 times longer than wide, with straight upper and convex lower margin; stylus long, short pubescent. Proboscis entirely brownish yellow. Palpus unmodified, elongate, brownish yellow, with 1 long black and 1 pale, shorter and thinner subapical setae.

Thorax brown in ground-colour, largely shining; prominent setae black; prothoracic sclerites (except postpronotal lobe) finely pollinose. Postpronotal lobe large, lacking conspicuous setae. Mesonotum with 1 strong notopleural and 2 scutellar setae; acrostichals and dorsocentrals minute, uniserial, lacking on prescutellar depression.

Legs long, with complicated colour pattern; fore femur with brown elongate ventral patch basally; fore tibia brown on apical 1/4; fore basitarsus brown on apical 1/3, tarsomeres 2–4 almost entirely (except extreme base), tarsomere 5 entirely brown; mid femur with small brownish subapical patch dorsally; mid tibia entirely brownish; mid tarsomeres 1–2 brownish apically, tarsomeres 3–5 becoming gradually darker brown toward tarsomere 5; hind femur brown on apical 1/4; hind tibia brown on about apical 2/3; hind tarsus almost entirely brownish (except extreme base of tarsomeres 1 and 2); otherwise legs reddish yellow. Coxae with black setae of different lengths; no setae between fore and mid coxae. Fore femur strongly thickened, with minute ventral setulae. Fore tibia spindle-like, mostly bare posteriorly but with rather long curved thin setae along bare space. Mid femur slender, with minute anteroventral and posteroventral spinule-like setulae, bearing 3 black spinelike setae of different lengths near base. Mid tibia with shallow subapical excision, bearing black ventral spinule-like setulae. Hind femur slender, with rows of short anteroventral and posteroventral setae. Hind tibia slender, lacking prominent bristles, with rounded posterior apical comb.

Wing ( Fig. 26 ) normally developed, rounded at apex, with typical venation for the genus; largely finely brownish infuscate, with large brown patch near apices of veins R1 and R2+3. One short basal costal seta present. Vein R1 meeting costa beyond wing midway. Proximal section of vein R4+5 considerably longer than Rs. Vein R2+3 straight. Veins R4+5 and M1+2 parallel toward wing-apex. Crossveins r-m and bm-cu separated. Cells br and bm extending to about wing midway. Halter with yellow stem and brown knob.

Abdomen brown, subshining, covered mostly with scattered, short, black setulae; segments 7 and 8 with moderately long setae. Terminalia ( Figs 7–9 ) moderately large, dark brown, elongate oval. Right cercus moderately long, rather broad, rounded apically, with numerous unmodified setae of different lengths. Left cercus short, narrowed apically, with several unmodified setae of different lengths. Right epandrial lamella subtriangular (viewed laterally), with large subglobular ventral process in subapical part, bearing numerous setae of different lengths. Right surstylus long, narrow, bent inward, with several unmodified setae on inner side and apically. Left surstylus subtriangular, with several long marginal bristles.

Female. Fore tibia with unmodified setation; mid tibia unmodified, slender. Otherwise as in male. Cercus brown, long.

Material examined. Holotype male: THAILAND Chiang Mai prov., Doi Inthanon NP summit marsh 18°35.361'N 98°29.157'E 2500 m Malaise trap 9–16.viii.2006 Y. Areeluck leg. T177.

Paratypes: 1 male, THAILAND Chiang Mai prov., Doi Inthanon NP summit marsh 18°35.361'N 98°29.157'E 2500 m Malaise trap 2–8.vii.2006 Y. Areeluck leg. T53; 1 male, Doi Inthanon NP summit marsh 18°35.361'N 98°29.157'E 2500 m Malaise trap 16–24.viii.2006 Y. Areeluck leg. T184; 1 female, Doi Inthanon NP summit marsh 18°35.361'N 98°29.157'E 2500 m Malaise trap 2–9.viii.2006 Y. Areeluck leg. T124.

Derivatio nominis. The epithet “ tiger ” alludes to the name of the TIGER Project.

Distribution. Thailand.

Remarks. The precise relationships of T. tigeri sp. nov. are unclear beyond its inclusion in the T. luang group. The new species can be distinguished from other species known from the Oriental Region as it is outlined in the key.

Figures

FIGURES 7 – 9. Tachydromia tigeri sp. nov. 7. right epandrial lamella, ventral view. 8. epandrium with cerci. 9. left surstylus, lateral view. Scale 0.1 mm.

FIGURES 24 – 31. Wings. 24. Tachydromia phanensis sp. nov. 25. Tachydromia phu sp. nov. 26. Tachydromia tigeri sp. nov. 27. Tachydromia ocellata sp. nov. male. 28. Tachydromia luang Shamshev, Grootaert. 29. Tachydromia monocercus sp. nov. 30. Tachydromia doi sp. nov. 31. Tachydromia ocellata sp. nov. female.