Revision of the described Nearctic species of the genus Tachydromia Meigen (Diptera: Hybotidae) Author Shamshev, Igor V. Zoological Institute of Russian Academy of Sciences, Universitetskaja nab. 1, St. Petersburg, 199034, Russia & All-Russian Institute of Plant Protection, St. Petersburg, 188620, Russia Author Grootaert, Patrick Royal Belgian Institute of Natural Sciences, Vautierstraat 29, B- 1000 Brussels, Belgium text Zootaxa 2024 2024-01-19 5403 2 151 196 http://dx.doi.org/10.11646/zootaxa.5403.2.1 journal article 10.11646/zootaxa.5403.2.1 1175-5326 10561768 3AC6ED7F-CD1E-4666-A1A8-FA686639815E Tachydromia pseliophora Melander ( Fig. 14 ) Tachydromia pseliophora Melander, 1928: 281 . Type locality: USA , “ Los Cerrites , California ”. Notes on type series. Melander (1928) noted the following material: “ four specimens , Los Cerrites , California , April 3, 1915 , collected by M.C. Van Duzee ” . Type material examined. SYNTYPES : 1 ♂ , 1 ♀ , Los Cerritos, Cal., 3.04.1915 , M.C. Van Duzee // Paratype , Tachydromia pseliophora Mel. [red label, species name hand-written] // Tachydromia pseliophora Mel. [hand-written] // A.L. Melander Collection 1961 ( USNM ). Recognition. The species is distinguished by the following combination of characters: proepisternum shiny; wing with entirely separated brownish bands; in male fore tibia with 2 black spots anteriorly. Redescription. Male. Length: body 1.9 mm , wing 1.8 mm . Head black. Occiput with patch of fine pruinosity above neck, vertex shiny; 2 inclinate, short, black vertical setae; some scattered black setae around neck and near mouth-opening; row of pale minute postoculars. Ocellar triangle shiny, ocellars very short. Frons shiny, slightly broadened towards ocellar triangle; above antennae nearly 2.0 times as broad as anterior ocellus. Antenna with postpedicel and stylus brown, scape and pedicel yellowish. Postpedicel subglobular; stylus subapical, long. Proboscis brown. Palpus unmodified, elongate oval, somewhat shorter than proboscis, brownish; clothed in scattered dark setae, with 1 short black subapical seta. Thorax blackish brown, largely shiny; prosternum faintly whitish grey tomentose, scutellum and postnotum faintly greyish tomentose. Postpronotal lobe large, elongate oval, lacking conspicuous setae, with scattered minute setulae. Mesonotum with 1 black, short strong notopleural, 1 minute postalar and 4 scutellars (inclinate apical pair nearly as long as notopleural setae, laterals shorter and thinner); some minute setulae present behind postpronotal lobe and on notopleural depression anteriorly; acrostichals lacking; dorsocentrals arranged in 2 irregular rows anteriorly (almost uniserial in female), becoming uniserial toward scutellum, numerous, mostly minute, 1 prescutellar pair somewhat longer (nearly as long as scutellar lateral setae). Leg colour: largely yellowish; fore and mid femora somewhat brownish on subapical part dorsally, hind femur brownish on apical 3/4; fore tibia with 2 black spots anteriorly (first spot just before middle, second spot subapical), hind tibia almost entirely brownish (except extreme base); fore and mid tarsomere 4 brownish yellow, tarsomere 5 blackish, hind basitarsus almost entirely yellow (except apex), tarsomeres 2–5 brownish. Fore coxa clothed in unmodified setae, longer and stronger apically, whitish pruinose anteriorly. Fore femur thickened; pubescent ventrally, with short anteroventral and posteroventral brownish yellow setulae becoming longer closer to base. Fore tibia somewhat spindle-shaped, flattened on broader part, with denser setulae on black spots anteriorly. Mid femur slender; rows of black anteroventral and posteroventral spinule-like setulae becoming longer closer to base. Mid tibia lacking apical projection, bearing ventral spinule-like setulae. Hind leg unmodified; hind femur with rows of short anterodorsal and posterodorsal setae. Wing normally developed, rounded at apex; two broad brownish bands entirely separated. One short costal seta. Rs short. Vein R 1 meeting costa before wing mid-length. Vein R 2+3 almost straight, slightly arched, gently upturned meeting costa, thin throughout. Veins R 4+5 and M 1+2 convergent towards wing apex. Vein M 4 distinct throughout. Cell r 1 narrower than subequal cells r 2+3 and r 4+5 . Crossveins r-m and bm-m broadly separated. Calypter brownish, with scattered fringe. Halter with pale knob and brownish yellow stem. Abdomen largely brownish, segments 1–2 and posterior margin of segment 3 brownish yellow; shiny, covered with scattered black setae longer on pregenital segments. Hypopygium ( Fig. 14A–C ) rather large, elongate oval, blackish brown. Right epandrial lamella ( Fig. 14B ) rather subglobular viewed laterally, bearing 5 unmodified long setae apically; broad ventral projection bearing 4 long, flattened setae. Right surstylus separated from epandrial lamella, bilobed; ventral lobe digitiform, rather broad, long; dorsal lobe short, curved; both lobes with simple, short setae. Left epandrial lamella ( Fig. 14C ) small, with short setae apically. Left surstylus barely separated from epandrial lamella, elongate, excised apically, with scattered, unmodified short setae. Cerci ( Fig. 14A ) separated, with unmodified short to moderately long setae; right cercus digitiform, narrow, moderately long; left cercus somewhat longer than right cercus, mostly broad, narrowed apically. Hypoproct slightly produced beyond apices of cerci. FIGURE 14. Tachydromia pseliophora Melander , male terminalia (USA, California; syntype, USNM). A. Hypopygium, dorsal view. B. Right epandrial lamella and right surstylus, lateral view. C. Left epandrial lamella and left surstylus, lateral view. Abbreviations: cerc—cercus; epand—epandrium; hypd—hypandrium; hyprct—hypoproct; lft sur—left surstylus; rt cerc—right cercus; rt sur—right surstylus. A–C: scale bar is 0.1 mm. Female. Fore tibia uniformly yellow, otherwise as in male. Cercus brownish, long, slender, with minute setulae. Remarks. Tachydromia pseliophora belongs to the T . fuscinervis group and is very similar to T . harti . Distribution . USA ( California ).