Tachypeza vriesi, Grootaert, Patrick & Shamshev, Igor, 2009

Grootaert, Patrick & Shamshev, Igor, 2009, First records of Tachydromia Meigen and Tachypeza Meigen (Diptera: Hybotidae) from Viet Nam, with descriptions of four new species, Zootaxa 2249, pp. 33-43 : 41-43

Tachypeza vriesi sp. nov.

( Figs. 10–12 )

Diagnosis. Recognized by entirely pollinose thorax, palpus with very long black subapical seta, 2 notopleural setae and fore coxa with 1 short subapical spine.

Description. Male. Body 3.1 mm, wing 2.9 mm. Head black. Eyes extending beyond ocellar tubercle. Frons densely pollinose, rather narrow and only slightly widened toward ocellar tubercle. Ocellars minute. Occiput entirely pollinose; with 2 closely set postverticals (missing in holotype) and numerous fine pale setae near neck and on lower part. Antenna rather brownish yellow, style brownish; postpedicel short, elongate oval; stylus subapical, very long, short pubescent. Proboscis brownish yellow, rather long. Palpus unmodified, short, elongate oval, brownish yellow, with 1 very long black and 1 short pale subapical setae, and 2 short black setae basally.

Thorax largely brown, pleura yellowish to brownish yellow in different extent; entirely pollinose. Postpronotal lobe large, with some minute setulae. Mesonotum with 2 strong notopleural (posterior one longer), 1 minute postalar and 4 scutellar setae (apical pair missing, laterals minute); acrostichals and dorsocentrals minute, the former multiserial, lacking on prescutellar depression, the latter uniserial, uniform, including prescutellar pair.

Legs with complicated color pattern; coxae and trochanters yellow; femora yellow but with narrow brownish vitta along entire length posteriorly and hind femur narrowly brown apically; fore and mid tibiae brownish (fore tibia somewhat darker on subapical portion anteriorly), hind tibia largely yellow, contrastingly dark brown on about apical 1/5; fore and mid tarsomere 4 largely brownish, tarsomere 5 entire brownish, otherwise fore and mid tarsus yellow, hind basitarsus yellow on basal half, otherwise hind tarsus brownish. Fore coxa with numerous thin bristles of different lengths apically, otherwise clothed in minute setulae, bearing 1 short subapical spine on inner side. Mid coxa with long black seta on outer face. Mid and hind trochanters with long seta. Fore femur thickened, with minute anteroventral and posteroventral setulae more numerous basally, bearing several anteroventral subbasal spinules. Fore tibia slightly thickened, with row of ventral spinules. Fore basitarsus with rows of ventral spinules. Mid femur slender, with regular rows of minute anteroventral and longer and stronger posteroventral setulae, bearing short ventral spine near base. Mid tibia with small subapical ventral excision, bearing ventral spinules. Mid tarsus unmodified. Hind legs long, slender, with inconspicuous setation.

Wing normally developed, rounded at apex, largely finely brownish infuscate, with darker space round subapical part of vein R2+3. Basal costal seta inconspicuous. 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. Squama pale colored and fringed. Halter pale yellow.

Abdomen with brownish, subshining, well sclerotised tergites and sternites (except pale segment 1) clothed largely in scattered minute setulae; pregenital sclerites (especially sternites) with longer posteromarginal setae; pregenital segments unmodified (except segment 8). Sclerites of abdominal segment 8 narrowly fused posteriorly, tergite 8 broadly membranous leaving strongly sclerotised narrow anterior margin and lateral subtriangular spaces.

Terminalia ( Figs. 10–12 ) rather small, brown. Right cercus rather digitiform, broader on about apical half, with some moderately long unmodified setae. Left cercus digitiform, shorter and narrower than right cercus, with several unmodified setae of different lengths. Right epandrial lamella conical, with several long unmodified setae, bearing large subglobular ventral projection. Right surstylus differentiated from epandrium, with several spinules on inner face. Left epandrial lamella small, conical, with 2 short subapical spines. Left surstylus barely differentiated from epandrium, with short unmodified setae. Hypandrium strongly humped, with 3 short setae.

Female. Unknown.

Material examined. Holotype male, VIET NAM: Lao Cai Prov., Sa Pa, Sin Chai, c. 1900 m, 11.09– 21.10 .1999, Malaise trap, leg. R. de Vries [Naturalis].

Derivatio nominis. The specific epithet refers to the collector's name, Rob de Vries.

Distribution. Viet Nam.

Remarks. Among Palaearctic species of Tachypeza the new species is comparable with T. fuscipennis (Fallén) . However, T. vriesi sp. nov. differs by the color pattern of legs and by the presence of a black subapical spine on the fore coxae (similar to T. nubila (Meigen)) .

Figures

FIGURES 10 – 12. Tachypeza vriesi sp. nov. 10. right epandrial lamella, ventral view. 11. hypopygium, dorsal view. 12. left epandrial lamella, lateral view.