Syneches Walker. Proepisternum 1852

Genus Syneches Walker

Syneches Walker, 1852: 165; Bezzi, 1904: 329 (citation, key for subgenera); Melander, 1928: 38 (cit., key for subgenera); 1965: 448 (catalogue); Smith, 1967: 9; 1969: 84; 1975: 190; 1980: 435; 1989: 389 (cat.); Wilder, 1974: 2 (revision Nearctic spp.); Chvála, 1983: 104 (cit.); Chvála & Kovalev, 1989: 184 (cat.); Yang et al., 2007: 306 (cat.); Sinclair, 2011 (rev. Fijian species); Menezes & Ale-Rocha, 2016: 403 (rev. Amazonian spp.). Type-species: Syneches simplex Walker, 1852 (monotype).

Pterospilus Rondani, 1856: 152; Melander, 1928: 38 (synonym). Type-species: Asilus muscarius Fabricius, 1794 (mon.).

Harpamerus Bigot, 1859: 306; Bezzi, 1904: 329 (as subgenus); Frey, 1938: 53 (key); Yang & Yang, 2004: 115 (as genus); Yang et al., 2007: 301 (cat.); Sinclair, 2011: 359 (syn.). Type-species: Harpamerus signatus Bigot, 1859 (mon.).

Epiceia Walker, 1860: 149; Bezzi, 1904: 329 (as subgenus); Frey, 1938: 53 (key); Yang et al., 2007: 301 (syn.). Type-species: Epiceia ferruginea Walker, 1860 (mon.).

Parahybos Kertész, 1899: 176; Melander, 1928: 45 (cit.); Frey, 1938: 53 (key); 1953: 67 (as subgenus); Smith, 1975: 188; 1980: 434 (cat.); 1989: 389 (cat., syn.); Yang & Yang, 2004: 232 (as genus); Yang et al., 2007: 301 (cat.); Sinclair, 2011: 359 (syn.). Type-species: Parahybos iridipennis Kertész, 1899 (mon.).

Diagnosis. Length: 1.8–7.5 mm. Color: yellow to black. Body ranging from slender to robust with slender legs, or with swollen hind femur; scutum normally arched; eyes in general flat on frons; upper facets often wider than lower; postpedicel short and oval (longer in S. longiflagellatus), often bearing a long dorsal seta and the antennal stylus apical to subapical; palpus short and bristly, 3 to 4 x shorter than proboscis, with 1 long apical bristle; proboscis long with labellum sclerotized, lacking pseudotracheae; postcranium concave, with distinct postocellar sclerite; vein Rs long, beginning on basal half of cell br; male terminalia symmetrical and rotated 45–90° to the right.

Distribution. Cosmopolitan.

Key to Brazilian species of Syneches Walker

1 Postpedicel elongate, about 3 x longer than scape and pedicel combined (Fig. 27B); scutum yellow to pale brown, with quadrangular dark brown spot on anterior third (Figs 27C, D)........................ S. longiflagellatus Ale-Rocha & Vieira

- Postpedicel usually slightly longer than scape and pedicel combined (Figs 7C, 43C); scutum with variable color, never with quadrangular dark brown spot on anterior third (Figs 1A, B)................................................... 2

2 Scutum broader than mesopleuron in lateral view, usually pyramidal-shaped (Figs 6B, 7B); femora mostly brown to black (Figs 6A, 7A); small species (1.8–3.0 mm)...................................................................... 3

- Scutum as broad or narrower than mesopleuron in lateral view, usually dome-shaped (Figs 1A, 3B); femora with variable color (Figs 4A, 8A); small to large species (3–7.0 mm)............................................................ 8

3 Pterostigma split into two spots, one posterior to apex of R 1 and one filling apex of cell r 1 (Figs 6E, 29E, 47E)........... 4

- Pterostigma continuous, single spot (Fig. 7F), or inconspicuous (Fig. 12E)........................................ 6

4 Second section of M 1 about 1/4–1/2 length of crossvein r-m; R 2+3 strongly curved anteriorly, forming right angle with vein C (Fig. 6E)................................................................. S. angulatus Menezes & Ale-Rocha

- Second section of M 1 as long or longer than crossvein r-m; R 2+3 gently curved anteriorly, not forming right angle with vein C (Figs 29E, 47E)....................................................................................... 5

5 Postpedicel dark brown, yellow on apical half (Fig. 47C), sometimes varying from entirely dark brown to entirely yellow; scutum with dc stripe of gray pruinescence, one circle of gray pruinescence on npl and other just above npl (Fig. 47B); pterostigma extended beyond apex of cell r 1 (Fig. 47E); distal margin of hypandrium rather convex, with pair of bristles inserted very close to each other (Ale-Rocha & Vieira 2008, Fig. 30)...................................... S. vidali Ale-Rocha & Vieira

- Postpedicel wholly dark brown (Fig. 29C); scutum with dc stripe with pale pruinescence, without circles of gray pruinescence (Fig. 29B); pterostigma not extended beyond apex of cell r 1 (Fig. 29E); distal margin of hypandrium rather concave, with pair of bristles inserted far from each other (Menezes & Ale-Rocha 2016, fig. 60)......... S. maculosum Menezes & Ale-Rocha

6 Tibiae yellow to dark yellow, hind tarsomere 1 wholly yellow (Figs 36A, D); epandrium with median apical projection (Rafael & Ale-Rocha 1995, fig. 51)............................................................. S. pyramidatus Bezzi

- Tibiae predominantly dark brown to black, hind tarsomere 1 brown with base and apex yellow (Figs 7A, 12A, D); epandrium with dorsoapical projection............................................................................. 7

7 Prescutellar disc and scutellum covered with dense gray pruinescence (Fig. 7D); pterostigma small, somewhat triangular, brown, or just darkening posterior to apex of R 1, wing slightly brownish (Fig. 7F).................... S. annulipes Bezzi

- Prescutellar disc and scutellum covered with reddish brown pruinescence; pterostigma inconspicuous, wing hyaline (Fig. 12E).................................................................... S. bilobatus Menezes & Ale-Rocha

8 Flies medium to large size (5–7.00 mm), with strong aspect (Figs 1A, 9A, 13A, 15A, 48A, B); scutellum with more than 16 bristles of various sizes; hind femur strongly swollen with 1AV and 1V rows of spiniform bristles inserted on short tubercles (Figs 13D, 15D); pterostigma colored (Figs 9E, 13E, 15E, 48H)................................................ 9

- Flies small to medium size (3–5.5 mm), with slender aspect (Figs 4A, 8A); scutellum usually with less than 16 bristles (only S. luteus has more than 16 bristles); hind femur variable in robustness and chaetotaxy; pterostigma colored or inconspicuous... .................................................................................................. 12

9 Pterostigma short and quadrangular, with brown stain at apex of R 2+3 and anterior to crossvein r-m (Fig. 48H) S. walkeri Smith

- Pterostigma elongate, 2 or 3 x longer than wide, oval, lacking brown stain at apex of R 2+3 and anterior to crossvein r-m (Figs 9E, 13E, 15E)....................................................................................... 10

10 Prosternum isolated, not fused to proepisternum (Fig. 2A; cf. also Menezes & Ale-Rocha 2016, fig. 2); wing dark brown, pterostigma not fading out distally (Fig. 9E); phallus without lateral flaps (Soares & Ale-Rocha 2018, fig. 1)............................................................................................. S. atratus Soares & Ale-Rocha

- Prosternum fused to proepisternum (Fig. 2C; cf. also Menezes & Ale-Rocha 2016, fig. 1); wing greyish or pale brown, pterostigma fading out distally (Figs 13E, 15E); phallus with lateral flaps (Fig. 14A).................................. 11

11 Pterostigma slender, about 3 x longer than wide, fading above, not touching costal margin in cell r 1 (Fig. 15E); antenna wholly dark brown (Figs 1A, 15C); proboscis and palpus pale brown to dark brown (Fig. 15C); fore tibia dark brown (Figs 1A, 15A– C); postgonite rounded at apex; epandrial lamella wide in lateral view, slightly narrower on apical half (Menezes & Ale-Rocha 2016, figs 34–35).................................................................... S. curvipes (Fabricius)

- Pterostigma broader than in S. curvipes, about 2 x longer than wide, fading distally, touching costal margin in cell r 1 (Fig. 13E); antenna wholly brown or with postpedicel yellow (Fig. 13C); proboscis and palpus yellow (Fig. 13C); fore tibia yellow (Fig. 13A); postgonite with truncated apex (Fig. 14A); epandrial lamella wide in lateral view, narrowing abruptly towards apex (boot-like shape) (Fig. 14C)............................................................... S. catarinae Smith

12 Ocellar triangle flat (Figs 8C, 30B, 38B); mid tibia with 2 bristles longer than mid tarsomere 1; hind femur usually with 1AV row of bristles inserted on finger-like tubercles (Fig. 38C).................................................... 13

- Ocellar triangle protuberant (Figs 1A, 3C, 10C); mid tibia usually lacking bristles longer than mid tarsomere 1 (S. exilis has long bristles on mid tibia, longer than mid tarsomere 1); hind femur without prominent finger-like tubercles (Figs 4D, 10D).. .................................................................................................. 15

13 Scutum covered with reddish brown pruinescence; prescutellar disc clearly contrasting with gray pruinescence and dc stripe of yellowish-gray pruinescence (Fig. 8B); hind tibia yellow with slender brown ring at mid-length (Fig. 8A); hind femur with 1AV row of spiniform bristles inserted on small tubercles (Figs 8E, F)................... S. applanatus Menezes & Ale-Rocha

- Scutum covered with homogeneous pruinescence (Figs 30A, 38A), lacking dc stripe; hind tibia yellow or brown, lacking contrasting slender ring at mid-length (Figs 30C–D, 38C–D); hind femur with 1AV row of spiniform bristles inserted on finger-like tubercles (Figs 30C–D, 38C–D)......................................................................... 14

14 Hind femur brown, yellow at base (Figs 30C–D); wing hyaline, with infuscation on apical margin and at mid-length between R 1 and crossvein r-m; R 2+3 with apex strongly curved anteriorly, reaching vein C at right angle (Fig. 30E); hypandrium 2 x longer than wide (Menezes & Ale-Rocha 2016, fig. 67)................................................. S. manaos Smith

- Hind femur brown, with basal third to basal half yellow (Figs 38C–D); wing hyaline, lacking infuscation; R 2+3 with apex gently arched anteriorly, reaching vein C at acute angle (Fig. 38E); hypandrium elongated, about 3 x longer than wide (Ale-Rocha & Vieira 2008, fig. 2)........................................................................ S. repletus Bezzi

15 Scutum distinctly narrower than mesopleuron in lateral view (Figs 3B, 16B, 39B); prescutellar disc not distinctly flattened (mesopleuron measurements taken from end of notopleuron to mid coxa)........................................ 16

- Scutum as broad as mesopleuron or only slightly narrower than mesopleuron (Figs 13B, 18B); prescutellar disc distinctly flattened.............................................................................................. 18

16 Scutum orangish yellow; pleura yellow, except posterior half of anepisternum and central portion of katepisternum brown, forming large, well delimited vertical spot (Figs 39A, B); hind tibia yellow (Fig. 39D)................ S. sinclairi sp. nov.

- Scutum brown (Figs 3B, 16B); pleura variable in color, without well delimited vertical spot (Figs 3B, 16B); hind tibia brown (Figs 3D, 16D)...................................................................................... 17

17 Antenna yellow, except postpedicel brown (Fig. 3C); palpus brown; pleura brown to pale brown (Fig. 3C); hind femur slightly swollen (Fig. 3D); distal margin of hypandrium without digitiform projection (Menezes & Ale-Rocha 2016, fig. 4)............................................................................... S. amazonicus Menezes & Ale-Rocha

- Antenna brown, except postpedicel yellow (Fig. 16C); palpus yellow; pleura yellow, except anepisternum, upper half of anepimeron and laterotergite brown (Fig. 16C); hind femur strongly swollen (Fig. 16D); distal margin of hypandrium with two short digitiform projections medially (Figs 17A, D)........................................... S. digitatus sp. nov.

18 Pterostigma hyaline (Figs 26E, 28C, 31E)................................................................. 19

- Pterostigma colored (Figs 4E, 10F, 19F).................................................................. 21

19 Species medium size (5.0 mm); scutellum with more than 16 bristles........................... S. luteus (Wiedemann)

- Species small size (3.0 mm); scutellum with less than 16 bristles............................................... 20

20 Antenna yellow with postpedicel varying from yellow to dark brown (Fig. 31C); prescutellar disc and postalar callus covered with dense gray pruinescence (Fig. 31B)..................................................... S. moraballi Smith

- Antenna entirely dark brown (Fig. 26C); prescutellar disc and postalar callus covered with reddish brown pruinescence................................................................................ S. limeirai Soares & Ale-Rocha

21 Pterostigma quadrangular or rectangular, ending far from apex of cell r 1 (Figs 37E, 43H); shape of proepisternum and prosternum variable (however, all species with proepisternum long (Fig. 2B) or fused to prosternum forming precoxal bridge keyed here) (Fig. 2C)...................................................................................... 22

- Pterostigma variable, but not quadrangular or rectangular, sometimes filling apex of cell r 1; proepisternum short, prosternum isolated, not fused to proepisternum, both distinctly separated and never forming precoxal bridge (Fig. 2A)............. 23

22 Hind femur yellow (Fig. 37D); pterostigma short and quadrangular (Fig. 37E); prosternum fused to proepisternum (Fig. 2C)............................................................................. S. rafaeli Ale-Rocha & Vieira

- Hind femur brown with yellow subapical ring (Figs 43B, F–G); pterostigma somewhat long, rectangular (Fig. 43H); proepisternum long, not fused to prosternum (Fig. 2B)...................................... S. striatus Menezes & Ale-Rocha

23 Scutum mostly orangish yellow, clearly contrasting with dark pronotum......................................... 24

- Scutum mostly brown to dark brown, concolorous with pronotum.............................................. 25

24 Scutum with dark brown acr stripe absent on prescutellar disc (Fig. 19D); hind tibia yellow, dark on apical fourth (Fig. 19E); second section of M 1 as long as crossvein r-m (Fig. 19F)....................................... S. fasciatus sp. nov.

- Scutum lacking acr stripe; hind tibia yellow (Fig. 21C); second section of M 1 2 x longer than crossvein r-m (Fig. 21D)..................................................................................... S. flaviscutellatus sp. nov.

25 Hind femur yellow with apical third to apical half reddish brown, with 1AV row of long and sparse spiniform bristles (Figs 10D, 41D).............................................................................................. 26

- Hind femur mostly brown or yellow, lacking AV row of spiniform bristles, or present only on apical third.............. 27

26 Scutum homogeneously dark brown on ground color, covered with gray pruinescence, reddish brown on acr region, pale golden on dc stripe, absent only on prescutellar disc, visible in anterior and dorsolateral views (Figs 10B, E); phallus with truncate apex, with long and strong lateral flaps (Fig. 11A)............................................ S. barrettoi sp. nov.

- Scutum pale yellow to brown on ground color, covered with homogenous golden pruinescence, acr region with complete dark brown stripe (Fig. 41B); phallus with rounded apex, lateral flaps short and slender (Fig. 42A)............ S. smithi sp. nov.

27 Hind leg mostly brown (Figs 18D, 25D, 34D).............................................................. 28

- Hind leg mostly yellow (Figs 23D, 32C, 44D, 45D)......................................................... 30

28 Pterostigma narrow, about 6 x longer than wide (Fig. 18E); R 2+3 nearly straight at apex (Fig. 18E); apical scutellar bristles absent........................................................................ S. exilis Menezes & Ale-Rocha

- Pterostigma wide, 3 or 4 x longer than wide; R 2+3 slightly angulate at apex (Figs 25E, 34E); apical scutellar bristles present.. .................................................................................................. 29

29 Palpus brown; fore leg brown (Fig. 25A); hind femur brown (Fig. 25D).................. S. jauensis Ale-Rocha & Vieira

- Palpus yellow (Fig. 34C); fore leg yellow, except tarsomeres 3–5 brown (Fig. 34A); hind femur brown with base and preapical ring yellow (Fig. 34D)................................................................. S. plaumanni sp. nov.

30 Mid and hind coxae dark brown (Fig. 23A); hind femur with AV and V spiniform bristles inserted on short tubercles on apical third (Fig. 23D).......................................................................... S. fuscus sp. nov.

- Mid and hind coxae yellow (Fig. 4A); hind femur lacking spiniform bristles inserted on short tubercles (Figs 4D, 44D, 45D). .................................................................................................. 31

31 Pleura yellow, except anepisternum brown, anepimeron and laterotergite with small central spot brown (Fig. 4B); hind tibia brown on apical half, slightly paler on basal half (Fig. 4D); pterostigma wide, about 2 x longer than wide, filling apex of cell r 1 (Fig. 4E)............................................................................. S. amorimi sp. nov.

- Pleura predominantly pale brown to dark brown (Figs 44B, 45B); hind tibia yellow (Figs 44D, 45D); pterostigma narrow, at least 3 x longer than wide, not filling apex of cell r 1 (Figs 32D, 45E) ........................................................................... 32

32 Postpedicel brown to dark brown (Fig. 45C); pterostigma with short marginal proximal invagination (Fig. 45E); phallus with rounded apex, lateral flaps short, arising close to base of phallus (Fig. 46A)........................ S. tomentosus Smith

- Postpedicel yellow to pale yellow (Figs 32B, 44C); pterostigma lacking short marginal proximal invagination (Figs 32D, 44E); phallus with truncate apex or with weak concavity, lateral flaps long, arising from apical half or from apex of phallus (Fig. 33A).............................................................................................. 33

33 Scape and pedicel brown, postpedicel yellow to pale yellow (Figs 32A, B); fore tibia brown; hypandrium with distal margin trapezoidal, with median subtriangular protuberance, with 2 short apical projections (Fig. 33A)....... S. nordestino sp. nov.

- Antenna entirely yellow (Fig. 44C); fore tibia yellow (Fig. 44D); hypandrium slightly narrowed distally, largely cleft apically forming 2 large lobes (Menezes & Ale-Rocha 2016, fig. 88).......................S.tenebricusMenezes & Ale-Rocha

Syneches amazonicus Menezes & Ale-Rocha