Tachydromia phu, 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 : 25-27

Tachydromia phu sp. nov.

( Figs 4–6 , 25 )

Diagnosis. Palpus yellow. Legs largely yellow. Wing largely finely brownish infuscate, hyaline on subapical space, brown along anterior margin. Halter with brown knob. Male: fore tibia slightly curved (viewed dorsally), with ventral spinules.

Description. Male. Wing 2.3–2.4 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 finely pollinose; with 2 moderately long strong black 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 brownish yellow; postpedicel paler, yellow, short, elongate oval; stylus very long, brownish, short pubescent. Proboscis largely yellow, narrowly dark brown proximally. Palpus unmodified, short, elongate oval, yellow, with 1 long black subapical seta and 4–5 yellowish short setae basally.

Thorax dark brown in ground-colour, largely shining; prominent setae black; prothoracic sclerites (except postpronotal lobe) pollinose. Postpronotal lobe large, lacking conspicuous setae. Mesonotum with 2 strong notopleural and 2 scutellar setae; Acrostichals and dorsocentrals minute; the former multiserial, lacking on prescutellar depression; the latter uniserial anteriorly, arranged in 3–4 irregular rows and hardly separated from acrostichals posteriorly.

Legs long, largely yellow; mid coxa with brownish patch laterally; fore femur indistinctly brownish clouded posteriorly on subapical space; mid tibia brownish on apical 2/3 anteriorly and (less distinct) on basal 2/3 posteriorly; fore tarsomere 4 brownish yellow on apex, tarsomere 5 brown; mid tibia brown basally and becoming gradually paler toward apex; mid tarsomere 4 brownish yellow, tarsomere 5 brown; hind femur broadly brownish on middle part; hind tibia dark brown on about apical half. Coxae mostly with pale hair-like setae of different lengths; several pale hair-like setae present between fore and mid coxae. Fore femur strongly thickened, with tuft of short black spinule-like setae near middle and several spinule-like setulae basally. Fore tibia swollen and slightly curved (viewed dorsally), with ventral spinules over entire length (stronger on apical half) and several spinule-like setulae posteriorly near middle. Fore basitarsus with ventral spinules becoming shorter apically. Mid femur slender, with anteroventral and posteroventral very short (the latter longer) spinule-like setae becoming somewhat longer toward base of femur, bearing 4–5 moderately long strong setae near base. Mid tibia slender, lacking prominent bristles, with some ventral spinule-like setulae. Hind femur slender, with row of short strong anteroventral setae becoming minute basally. Hind tibia slightly thickened on about apical half, lacking prominent bristles, with narrow pointed posterior apical comb. Tarsi of all legs unmodified (hind tarsus missing).

Wing ( Fig. 25 ) normally developed, rounded at apex, with typical venation for the genus; largely finely brownish infuscate, hyaline on subapical space, brown along anterior margin. 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 wing midway. Halter with pale stem and brown knob.

Abdomen with segment 1 pale (viewed dorsally with narrow brownish patch), otherwise brown, subshining, covered mostly with scattered, short, black setulae; segments 7 and 8 with moderately long setae. Terminalia ( Figs 4–6 ) large, dark brown, elongate oval. Right cercus rather long, subrectangular, with numerous moderately long marginal setae in subapical part. Left cercus quite long but somewhat shorter than right cercus, slightly curved, pointed apically, with numerous 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 rather subtriangular, with 1 very long bristle on lower margin about middle, 4 strong long bristles on upper margin and some unmodified setae of different lengths apically.

Female. Fore coxa sometimes brownish near base anteriorly; hind tarsus brownish. Fore femur with numerous unmodified spinules ventrally; fore tibia evenly thickened, with unmodified ventral spinules; mid femur with short bristles near base; hind femur with hardly prominent anteroventral setae. Otherwise as in male. Cercus brownish, short.

Material examined. Holotype male: THAILAND Loei prov., Phu Ruea NP office 17°28.805'N 101°21.242'E 870 m Malaise trap 5–12.vii.2006 Patikhom Tamtip leg. T312.

Paratypes: 1 female, THAILAND Chiang Mai prov., Doi Inthanon NP Vachiratharn Falls 18°32.311'N 98°36.048'E 700 m Malaise trap 12–19.x.2006 Y. Areeluck leg. T366; 1 female, Doi Inthanon NP campground pond 18°32.657'N 98°31.482'E 1200 m Malaise trap 2–10.xi.2006 Y. Areeluck leg. T385; 1 female, Doi Inthanon NP Vachiratharn Falls 18°32.311'N 98°36.048'E 700 m Malaise trap 27.ix–5.x.2006 Y. Areeluck leg. T347.

Derivatio nominis. The specific epithet alludes to the fact that the species was found on a mountain (“ Phu kao” is Thai for mountain though generally only the word “ Phu ” is used to indicate mountain).

Distribution. Thailand.

Remarks. The new species is closely related to T. phanensis sp. nov. sharing similar setation of the left surstylus (1 very long and several strong bristles). The main distinguishing features between these species are given in the key.

Figures

FIGURES 4 – 6. Tachydromia phu sp. nov. 4. right epandrial lamella, ventral view. 5. epandrium with cerci. 6. 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.