Tachydromia doi, 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 : 34-36

Tachydromia doi sp. nov.

( Figs 20–23 , 30 )

Diagnosis. Palpus yellow. Legs almost entirely yellow; fore tarsomeres 4–5 entirely and hind tibia on basal half brownish. Wing with large brownish patch on subapical part. Halter yellow. Male: mid femur and mid tibia with subbasal and subapical excision, respectively.

Description. Male. Wing 2.5–2.7 mm. Head black in ground-colour. Eyes extending beyond ocellar tubercle. Frons shining, slightly widened toward ocellar tubercle, above antennae nearly as broad as anterior ocellus. Two pairs of moderately long ocellars. Occiput shining; with 2 long dark setae in upper part, several similar setae on middle part laterally and some pale hair-like setae near neck and on lower part. Basal antennal segments brownish yellow; postpedicel paler, yellowish, short, oval; stylus long, brownish, short pubescent. Proboscis entirely brown. Palpus unmodified, elongate, yellow, with 1 long yellow subapical seta.

Thorax brown in ground-colour, largely shining; prominent setae black; prothoracic sclerites (except postpronotal lobe) pollinose. Postpronotal lobe large, lacking conspicuous setae. Mesonotum with 1 thin notopleural, 1 postalar and 2 scutellar setae; acrostichals lacking; dorsocentrals uniserial, few in number, mostly minute, 1 presutural pair long (as long as scutellars).

Legs long, almost entirely yellow; fore tibia brownish yellow anteriorly and posteriorly; fore tarsomeres 4 and 5 brown (except extreme base); mid and hind tarsomere 4 brownish yellow, tarsomere 5 brownish; hind tibia brownish on basal half. Coxae with pale hair-like setae of different length; no setae between fore and mid coxae. Fore femur strongly thickened, with anteroventral and posteroventral short spinule-like setulae, bearing 2 long setae near base. Fore tibia evenly swollen, with subapical ventral comb of several black setulae. Fore tarsomere 1 with patch of black ventral spinules on subapical portion. Mid femur slightly thickened, with shallow excavation and small ventral swelling nearer to base, bearing 2 dark spinules sitting on swelling (before excavation) and 1 smaller dark spinule beyond excavation, with 2 long yellowish setae near base and some anteroventral and posteroventral spinules on apical part. Mid tibia with shallow excision on apical part, bearing some ventral spinule-like setulae before excision. Hind femur slender, with rows of short anterodorsal and posteroventral setae. Hind tibia slender, lacking prominent bristles, with narrow pointed posterior apical comb.

Wing ( Fig. 30 ) normally developed, rounded at apex, with typical venation for the genus; largely hyaline, with large brownish patch near meeting point of vein R2+3 with costa, which becomes gradually paler toward lower margin of the wing. One short basal costal seta present. Vein R1 meeting costa somewhat before wing midway. Proximal section of vein R4+5 subequal to 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 1/3 of wing. Halter yellow.

Abdomen brown, subshining, covered mostly with scattered, short, black setulae; segments 7 and 8 with moderately long setae. Terminalia ( Figs 20–23 ) moderately large, dark brown, elongate oval. Right cercus small, deeply concave apically, with scattered short setulae. Left cercus rather short, subrectangular (subtriangular viewed laterally), with numerous short setae on subapical part. Right epandrial lamella subglobular (viewed laterally), covered with numerous setae of different lengths. Right surstylus rather short, bilobed; upper lobe bearing long black subapical spine; lower lobe curved inward, of complicated structure. Left surstylus as in Fig. 23 .

Female. Mid femur unmodified, with rows of anteroventral and posteroventral thin setae, the latter somewhat longer; mid tibia unmodified. Otherwise as in male. Cercus brownish, 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 13–21.ix.2006 Y. Areeluck leg. T252.

Paratypes: 2 males, 6 females, THAILAND Chiang Mai prov., Doi Inthanon NP summit marsh 18°35.361'N 98°29.157'E 2500 m Malaise trap 19–26.x.2006 Y. Areeluck leg. T374; 1 male, 2 females, Doi Inthanon NP summit marsh 18°35.361'N 98°29.157'E 2500 m Malaise trap 26.x–2.xi.2006 Y. Areeluck leg. T380; 2 males, 5 females, Doi Inthanon NP summit marsh 18°35.361'N 98°29.157'E 2500 m Malaise trap 5– 12.x.2006 Y. Areeluck leg. T362.

Derivatio nominis. The name “ doi ” means mountain in northern Thai language.

Distribution. Thailand.

Remarks. On the basis of pollinose prothoracic sclerites, straight vein R2+3, yellow palpi, 1 notopleural bristle and almost entire yellow legs the new species belongs to the T. terricola group sensu Chvála (1970) and it is similar to T. terricoloides Shamshev & Grootaert described from Loei Province of Thailand ( Shamshev & Grootaert 2005). The main distinguishing features between these species are given in the key.

Figures

FIGURES 20 – 23. Tachydromia doi sp. nov. 20. right epandrial lamella with surstylus. 21. right cercus, lateral view. 22. hypopygium, dorsal view. 23. left surstylus. 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.