Review of Brazilian species of Syneches Walker (Diptera, Hybotidae, Hybotinae), with description of ten new species Author Soares, Matheus M. M. 0000-0002-2355-1441 matheusmmsoares@gmail.com Author Freitas-Silva, Rafael A. P. 0000-0002-7560-4939 rpfreitas.silva@gmail.com Author Ale-Rocha, Rosaly 0000-0001-9874-9770 alerocha@inpa.gov.br text Zootaxa 2021 2021-10-11 5049 1 1 84 http://dx.doi.org/10.11646/zootaxa.5049.1.1 journal article 3976 10.11646/zootaxa.5049.1.1 5dc17a27-e095-4dc8-b10d-09fc935dbf45 1175-5326 5560580 F9647501-7F6B-4286-AEEE-19B620F697ED Syneches longiflagellatus Ale-Rocha & Vieira ( Figs 27A–F , 57 ) Syneches longiflagellatus Ale-Rocha & Vieira, 2008: 117 , figs 15–21, 38; Menezes & Ale-Rocha, 2016: 420 , fig. 120 (key, distr.). Type locality: Parque Nacional do Jaú, Amazonas, Brazil . Diagnosis. Medium size ( 3.6 mm ) ( Fig. 27A ). Antenna yellow, except postpedicel brown; postpedicel elongated, about 3 x longer than scape and pedicel combined, covered with dense pubescence ( Fig. 27B ). Prosternum fused to proepisternum. Scutum rounded, lower than mesopleuron in lateral view, yellow to pale brown, with a quadrangular dark brown spot on anterior third ( Figs 27C, D ). Legs yellow and slender ( Figs 27A, E ). Wing sub-hyaline; pterostigma pale brown, short, round, placed distal to apex of R 1 ( Fig. 27F ). Abdomen weakly sclerotized ( Fig. 27A ). Type material examined. HOLOTYPE ♂ ( INPA ) labelled: “ BRASIL , Amazonas , Parque Nacional do Jaú , 8–16.iv.2001 , 01°53′04″S 61°35′11″W ” “Arm [armadilha] Susp [suspensa] 20m , Floresta, Henriques & Vidal” “Holótipo, Syneches longiflagellatus Ale-Rocha & Vieira ” [red label] . Holotype condition: good; not dissected. Additional material examined. BRAZIL . Roraima : Xitei (Xidea), 02°36′24″N 63°52′17″W , 20.ix.1995 , L.S. Aquino , Arm. Malaise ( 1 ♀ , INPA ) . Amazonas : Manaus , Res. Ducke, Igarapé Barro Branco , Arm. Suspensa 20 m , 06–16.xii.2004 , Henriques, A. Leg. ( 1♂ , INPA ) ; Ipixuna , Rio Liberdade , Estirão da Preta , 07º21′46.7″S 71º52′07.1″W , 11–15.v.2011 , Arm. Malaise, J.A. Rafael , J.T. Câmara , R.F. Silva , A. Somavilla , C. Gonçalves , leg. ( 1 ♂ , INPA ) . FIGURE 26. Syneches limeirai Soares & Ale-Rocha, 2018 . A–D. Holotype male. A. Habitus, lateral view; B. Thorax, lateral view; C. Head, lateral view; D. Hind leg, anterior view. E. Paratype (male from type-locality). Wing. Distribution. Brazil (Amazonas and Roraima *) ( Fig. 57 ). Variation. The female from Roraima has the base of the postpedicel yellow and the scutum pale brown, slightly darker than on the holotype . Remarks. This unusual species is probably the most autapomorphic in the genus, by the following set of characters: postpedicel very long, about 3 x longer than preceding segments combined (the longest for the genus up-to-date), prosternum fused to proepisternum, abdomen weakly sclerotized and epandrial lamella with 1 long dorsoapical projection, about half-length of lamella ( Ale-Rocha & Vieira 2008 , fig. 17). The prosternum is fused to the proepisternum forming a precoxal bridge that does not seem to be homologous to that of the other Brazilian species of Syneches : S. catarinae , S. curvipes , S. rafaeli and S . walkeri because in these latter species, the prosternum has a wide connection with the proepisternum ( Fig. 2C ), while in S. longiflagellatus these sclerites are connected by a narrow region.