Tachydromia lilaniensis Smith, 1969

Shamshev, Igor & Grootaert, Patrick, 2010, The genus Tachydromia Meigen (Diptera: Hybotidae) from the Afrotropics, African Invertebrates 51 (1), pp. 207-207 : 210-212

Tachydromia lilaniensis Smith, 1969

Fig. 12

Tachydromia lilaniensis: Smith 1969: 71 , figs 77 (habitus), 79–81 (male terminalia). Type locality: South Africa, Natal , Lilani area nr Ahrens .

Diagnosis: Recognised by a combination of the following characters: occiput almost entirely shining; prothoracic sclerites (except postpronotal lobe) subshining; legs with fore and mid femora entirely yellow, hind femur largely brownish; wing with entirely separated bands; male mid femur with rows of unmodified anteroventral and posteroventral short setae.

Re-description:

Male:

Length: Body 2.0 mm, wing 1.9 mm.

Head: Eyes with posterior margin slightly produced beyond ocellar tubercle; vertex broader than frons in front of ocellar tubercle. Occiput including vertex almost entirely shining, very narrowly pollinose behind eyes; 2 moderately long postvertical setae. Ocellar tubercle shining, ocellars minute. Frons shining, slightly widened toward ocellar tubercle. Antenna with postpedicel and stylus brownish, scape and pedicel somewhat paler. Postpedicel subglobular; stylus subapical, very long, nearly 3× as long as pedicel and postpedicel combined. Palpus unmodified, slender, shorter than proboscis, blackish; clothed in silvery setae, with rather short (slightly shorter than palpus) black subapical seta.

Thorax: Black, almost entirely shining, prothoracic sclerites (except middle part of prosternum and postpronotal lobe) subshining, scutellum and mediotergite (= metanotum) densely tomentose. Postpronotal lobe large, elongate, lacking conspicuous setae. Mesonotum with 1 long notopleural, 1 similar postalar and 4 scutellars (lateral pair nearly as long as notopleural seta, apical pair longer, subparallel); acrostichals lacking; dorsocentrals uniserial, mostly minute, prescutellar pair nearly as long as lateral scutellars; mesosternum and metasternum bare between posterior four coxae.

Legs: With fore and hind coxae yellow, mid coxa brownish yellow basally; fore and mid femora entirely yellow, hind femur brownish on about apical 2/3; tibiae almost entirely brownish, yellowish on extreme base; tarsomeres 1 and 2 brownish apically, remaining tarsomeres entirely brownish. Coxae with yellowish unmodified setae. Fore femur thickened, pale pubescent ventrally, with yellowish anteroventral and posteroventral setulae becoming longer basally. Fore tibia slightly spindle-shaped. Mid femur slender, with rows of anteroventral and posteroventral spine-like setae (the latter darker and stronger). Mid tibia with short apical projection, bearing ventral spinule-like setulae. Hind leg unmodified, lacking prominent setae.

Wing: Normally developed, rounded at apex, with unmodified venation; two broad brownish bands separated throughout. One short costal bristle present. Vein R 2+3 strongly arched about middle toward costa. Veins R 4+5 and M 1+2 parallel near wing apex. Vein CuM very thin toward wing margin. Crossveins r–m and bm–cu broadly separated. Squama dusky yellow with concolorous fringe. Haltere with pale knob and brownish yellow stem.

Abdomen: Brownish, shining, covered with scattered black setae longer on pregenital segment; segments 1–7 unmodified. Terminalia small, rather elongate oval, blackish brown. Cerci (Smith’s fig. 80, unclear view) elongate-oval, narrower on apical part, with unmodified setae; left cercus somewhat longer. Right epandrial lamella (Smith’s fig. 79, lateral view) elongate-oval, covered with numerous setae of different lengths. Right surstylus (Smith’s fig. 81, viewed from inner side) differentiated from epandrium, bent inward, rather subtriangular, with several subapical spinules on inner side. Left surstylus undifferentiated from epandrium, digitiform, with several unmodified setae of different lengths; dorsal lobe of left epandrial lamella subtriangular, with several unmodified setae. Phallus short.

Female: Cercus brownish, long, slender, covered with minute setulae.

Holotype (examined): ơ SOUTH AFRICA: KwaZulu-Natal: Lilani area nr Ahrens [29°07'S: 30°51'E] Natal [hand-written]; iv.1962, collectors B. & P. Stuckenberg ; HOLOTYPE ơ Tachydromia lilaniensis [species name hand-written] K.G. V. Smith; NMSA –Dip. 09310. Note: Currently the holotype is in good condition but the postabdomen was dissected, macerated and pinned on a slide as a Canada balsam preparation by K.G. V. Smith .

Paratype (examined): LESOTHO: ^upper Cave Sandstone level, 6,000 ft; Roma Mission [29°27'S: 27°43'E] Maseru District Basutoland, B. & P. Stuckenberg, 4–13.i.1963; running over large lichenous boulders [hand-written] ; PARATYPE ^Tachydromia lilaniensis [species name hand-written] K.G.V. Smith; NMSA –Dip. 09305. Note: In the paratype female that we examined, the mid and hind legs, and the left fore tibia and tarsus, were missing .

Additional material: SOUTH AFRICA: Free State: 2^Sterkfontein Dam , 1780–1820 m, 28°29.72'S: 23°57.85'E, yellow pan traps, 10.xii.2005, M. Mostovski, in alcohol ( NMSA). Note: The specimens were collected near a temporary brook in a bush patch surrounded by grassland .

Distribution and seasonal occurrence: Eastern South Africa, Lesotho.According to labels, this species was collected in December, January and April.

Remarks: Smith (1969) described this species after several specimens taken from two localities in South Africa and Lesotho.

Figures

Fig. 12. Known distribution of Tachydromia species: • – T. freidbergi sp. n., 9 – T. lilaniensis, 0 – T. petrabilis,: – T. stuckenbergi sp. n., ♦ – Tachydromia sp.