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 peruicus Ya ng & Z h a n g (Figs. 7, 13) Syntomoneurum beckeri Parent 1931 : 17 . Syntormoneurum beckeri , misspelling by Parent 1931 : 17 . Tachytrechus beckeri (Parent) : Brooks (2005) . Tachytrechus peruicus Yang & Zhang in Yang et al. (2006) ; replacement name for Tachytrechus beckeri ( Parent) 1931 ; preoccupied by Tachytrechus beckeri Lichtwardt, 1917 . Diagnosis. Body length 5.3–5.4 mm ; wing length 5.3–5.5 mm ; face brownish with weak silvery-green reflections; male clypeus rounded below; 1 notopleural bristle; male fore tarsus distinctly silvery anteriorly, basitarsus lacking curved ventral setae, tarsomeres 3 and 4 flattened; hind femur mainly yellow with 1 anterior preapical bristle; bends in M distinct, obtuse; R4+5 and M subparallel distally (Figs. 7A, 7B); male wing (Fig. 7A) without costal swelling, with M and CuA1 thickened in basal section; male tergite 5 with posterior FIGURE 6. Tachytrechus giganteus (Brooks) : (A) male wing; (B) female wing; (C) male clypeus; (D) hypandrium (ventral view); (E) hypopygium (left lateral view). Adapted from Brooks & Wheeler (2002) . Abbreviations: A1: anal vein; apv lobe: apicoventral epandrial lobe; bv lobe: basiventral epandrial lobe; cerc: cercus; CuA1: 1st anterior branch of cubital vein; dm-cu: discal medial-cubital crossvein; hypd: hypandrium; M: medial vein; ph: phallus R1: 1 radial vein; R2+3: 2nd + 3rd radial vein; R4+5: 4th + 5th radial vein. FIGURE 7. Tachytrechus peruicus Yang & Zhang : (A) male wing; (B) female wing; (C) hypandrium (ventral view); (D) hypopygium (left lateral view). Figure D adapted from Brooks & Wheeler (2002) . Abbreviations: A1: anal vein; apv lobe: apicoventral epandrial lobe; bv lobe: basiventral epandrial lobe; cerc: cercus; CuA1: 1st anterior branch of cubital vein; dm-cu: discal medial-cubital crossvein; hypd: hypandrium; M: medial vein; pgt: postgonite; ph: phallus; R1: 1st radial vein; R2+3: 2nd + 3rd radial vein; R4+5: 4th + 5th radial vein; vsur: ventral lobe of surstylus. membraneous region bordering and mostly confined to dorsal portion of sclerite (cf. Fig 9 A); hypopygium (Figs. 7C, 7D): right and left basiventral epandrial lobes digitiform, right lobe longer; apicoventral epandrial lobe elongate, projected ventrally, with blunt, expanded apex bearing medial and outer setae; accessory epandrial process absent; apicolateral arm of postgonite with medial process present, with long hook-like process apically; cercus subrectangular in dorsal view, longer than wide, apical and lateral margin darkened; hypandrium narrow and symmetrical in ventral view; ventral surstylar lobe with series of parallel diagonal ridges on ventral surface; dorsal lobe about half as long as ventral lobe; phallus with fin-like projection before middle. Female sternite 8 divided medially, lacking deep medial invagination. Type material examined. Holotype Ψ, PERU : Cusco, Rio Urubamba, Umahuankilia, 500 m , 13.xi.1903 , C.A.W. Schnuse ( SMTD ). Other material examined. 1ɗ and 1Ψ, PERU : “?rég. côtière du N.” ( MNHN ). Distribution. Tachytrechus peruicus is known from the type locality near the Rio Urubamba in southeastern Peru , and from two specimens collected in the northern costal region of Peru ( Fig. 13 ); however the precise location of the latter locality is unknown and has been approximated on Fig. 13 (indicated with a “?”). Remarks. Yang and Zhang in Yang et al. (2006) proposed the name T. peruicus for T. beckeri ( Parent) 1931 in order to remove the homonymy with older name T. beckeri Lichtwardt 1917 , which resulted from the synonymy of Syntomoneurum with Tachytrechus by Brooks (2005) . The eversible glandular structure present in the other species was not found in the single male specimen of T. peruicus . However, the abdomen of this specimen was partially damaged prior to our examination and dissection, and the eversible gland, if present, may have been lost as a result.