The Tachytrechus alatus species group (= Syntomoneurum Becker) revisited: new species and revised species group limits (Diptera: Dolichopodidae) Author Brooks, Scott E. Author Cumming, Jeffrey M. text Zootaxa 2008 1676 1 27 journal article 10.5281/zenodo.180314 59f2f391-287e-465d-b396-9d11cd0a3378 1175-5326 180314 Tachytrechus alatus (Becker) (Figs. 1, 13) Syntomoneurum alatum Becker 1922 : 124 . Tachytrechus alatus (Becker) : Brooks 2005 : 121 . Diagnosis. Body length 6.4–7.1 mm , wing length 6.6 mm – 7.5 mm ; face and clypeus coppery with green reflections; clypeus rounded below; 1 notopleural bristle; male fore tarsus with basal three-quarters of basitarsus and tarsomeres 3–5 flattened and silvery on anterior surface; hind femur mainly yellow with 1 anterior preapical bristle; M with two 90° bends; R4+5 and M parallel distally (Figs. 1A, 1B); male wing with two adjacent swellings of the costa immediately proximal to insertion of R1, R2+3 very short, ending at costa before midpoint of wing, crossvein dm-cu close to wing base (Fig. 1A); female wing with R2+3 ending beyond midpoint of wing, crossvein dm-cu slightly before midpoint of wing (Fig. 1B); abdominal tergite 5 of male with large posterior membranous region, extended laterally as broad band to ventral margin of sclerite; hypopygium (Figs. 1C, 1D): right basiventral epandrial lobe with rounded basal projection and subquadrate inner distal projection, left basiventral epandrial lobe weakly developed; apicoventral epandrial lobe moderately developed, subquadrate in lateral view, short, projected posteriorly; accessory epandrial process present medial to apicoventral epandrial lobe; ventral surstylar lobe with series of parallel diagonal ridges on ventral surface; apicoventral arm of postgonite with medial process present, apex with hook-like process; cercus subquadrate in dorsal view, apical and lateral margin dark; right margin of hypandrium with pair of sickle-shaped projections; phallus with weakly sclerotized fin-like projection near middle. Female sternite 8 undivided, lacking medial invagination. Type material examined. Lectotype ɗ, PERU : Pasco, road to Rio Pichis, 300–700 m , 4.i.1904 , C.A.W. Schnuse ( ZMHB ). Paralectotypes , 1ɗ and 4Ψ ( SMTD ), 1Ψ ( ZMHB ) all from same locality as holotype . Distribution. Tachytrechus alatus is known only from the type locality near the Rio Pichis in Peru ( Fig. 13 ).