Syneches digitatus, Soares & Freitas-Silva & Ale-Rocha, 2021

Soares, Matheus M. M., Freitas-Silva, Rafael A. P. & Ale-Rocha, Rosaly, 2021, Review of Brazilian species of Syneches Walker (Diptera, Hybotidae, Hybotinae), with description of ten new species, Zootaxa 5049 (1), pp. 1-84 : 28-31

Syneches digitatus sp. nov.

( Figs 16A–E , 17A–E , 51 )

Diagnosis. Medium size (5.5 mm) ( Fig. 16A ). Antenna brown, except postpedicel yellow ( Fig. 16C ). Scutum rounded, narrower than mesopleuron in lateral view, covered with gray pruinescence ( Fig. 16B ); pleura yellow, except anepisternum brown, anterior margin of anepimeron and laterotergite pale brown ( Fig. 16B ). Mid tibia bearing 3 bristles longer than mid tarsomere 1 (1D on basal half, 1AV on mid-length and 1PV subapical); hind femur strongly swollen, yellow, with a wide ring at mid-length and apex brown ( Fig. 16D ). Wing sub-hyaline, pale brown; pterostigma long, subrectangular, brown, about 3 x longer than wide; second section of M 1 longer than crossvein r-m; cell bm slightly longer than cells br and cua ( Fig. 16E ).

Description. Holotype male ( Fig. 16A ). Body length: 5.5 mm; wing length: 4.5 mm. Head ( Fig. 16C ). Ocellar triangle protuberant, covered with gray pruinescence; 2 pairs of ocellar bristles, anterior pair long, about 2 x longer than posterior pair. Face black, covered with gray pruinescence.Antenna brown, with yellow postpedicel; postpedicel short, oval, about 1.4 x longer than wide, slightly longer than preceding segments combined, covered with golden pruinescence, bearing 1 long mediodorsal bristle slightly longer than postpedicel; stylus brown, about 3.5 x longer than preceding segments combined, short pubescent except apical 1/6 bare. Proboscis, palpifer and palpus dark yellow; palpus short, about 1/3 proboscis length, covered with golden pruinescence, with 2 bristles longer than palpus (1 medioventral, 1 apical) and 4 shorter bristles (2V on basal half, 2D on apical half). Postcranium black, covered with gray pruinescence. Thorax ( Fig. 16B ). Proepisternum short, prosternum isolated, not fused to proepisternum. Pronotum brown, with yellow margins, covered with golden pruinescence. Scutum rounded, narrower than mesopleuron in lateral view, brown, but posterior margin of pprn lb and pal cal pale yellow, covered with golden pruinescence. Scutellum pale brown, but anterior margin with median triangular pale brown spot, covered with gray pruinescence. Pleura yellow, except anepisternum, upper half of anepimeron and laterotergite brown. Mediotergite dark yellow. Chaetotaxy: scutum with acr 6-serial and dc uniserial, bristles short and sparse; prescutellar disc with 1 acr and 2 dc long, posterior dc longer, stronger and curved apically; 2 npl bristles long, strong and closely inserted; 2 pal bristles (anterior one short and thin, posterior one long and strong, about 4 x longer than anterior); scutellum with 11 marginal bristles (3 parallel apical pair, 1 long and strong subapical pair, about 2 x longer than apical pair, 3 lateral pairs, similar to apical pair). Legs (16A, D). Fore femur slightly swollen on basal half, mid femur slender, hind femur strongly swollen. Legs with fore tibia dark yellow, hind tibia, fore tarsus and mid and hind tarsomere 5, hind femur with wide ring at mid-length and apex brown, otherwise yellow. Chaetotaxy: fore tibia with 1D series of bristles increasing in size toward tibia apex; mid femur with 1AV and 1PV series of long and sparse bristles, shortening toward femur apex; mid tibia with 3 bristles longer than mid tarsomere 1 (1D on basal half, 1AV on mid-length, 1PV subapical) and 3 shorter bristles (1PV on mid-length, 1AV and 1D subapical); hind femur with 1AV series of spiniform bristles, long and sparse, inserted on short tubercles, several shorter V spiniform bristles on apical half, 3AD strong bristles on apical half; hind tibia with 1D long bristle on basal half and 3 long subapical bristles (1AD, 1D, 1PV). Wing ( Fig. 16E ). Sub-hyaline, pale brown; pterostigma long, subrectangular, brown, about 3 x longer than wide, extended from apex of R 1 and not filling apex of cell r 1; R 2+3 slightly angulate near apex; second section of M 1 longer than crossvein r-m; cell bm slightly longer than cells br and cua. Halter dark brown, except base of stem yellow. Abdomen ( Fig. 16A ). About 2.5 x longer than thorax. Dark brown, except tergites 1–2 brown, covered with reddish brown pruinescence; dorsal bristles short, laterodorsal bristles longer. Terminalia ( Figs 17A–D ) (Paratype, type-locality) with distal margin of hypandrium with two short digitiform projections, each one bearing 1 long bristle, slightly shorter than exposed part of phallus, hypandrium with 3 pairs of long bristles on apical third. Phallus long with rounded apex, shorter than postgonite, with short lateral flaps pointing to base of phallus, arising from middle of phallus. Postgonite long, wide on base and narrowing towards apex, curved apically reaching apex of epandrial lamella. Dorsal connection of epandrial lamellae narrow. Epandrial lamella wide in lateral view, narrowing gradually towards rounded apex.

Female. Similar to male. Terminalia ( Figs 16E, F ) with tergite 8 rectangular, about 2 x longer than wide, distal margin slightly concave; sternite 8 about 2.5 x longer than wide, narrower and membranous at mid-width of basal half, distal margin bearing long bristles; cercus long and narrow, longer than sternite 10.

Type material examined. HOLOTYPE ♂ ( MZUSP) labelled: “ Brasilien [ BRAZIL, Santa Catarina, Seara], Nova Teutônia, 27°11′B.52°23′L, xii.1970, Fritz Plaumann , 300–500 m ” “ HOLOTYPE, Syneches digitatus Soares, Freitas-Silva & Ale-Rocha ” [red label] . Holotype condition: good; not dissected. PARATYPES. Same data as holotype (3 ♂, 1 ♀, MZUSP; 4 ♂, 1 ♀, INPA; 1 ♂, CNC; 1 ♂, CAS; 1 ♂ NMNH; 1 ♂ DZUP) ; idem, xi.1970 (2 ♂, MZUSP; 1 ♀, CNC; 1 ♂ NHMUK; 1 ♂, DZUP). São Paulo: Cubatão, 15.xii.[19]55, Pereira et al. (1 ♀, MZUSP) ; Salesópolis, Est. Biol. Boracéia, iii.1969 (1 ♀, INPA) .

Distribution. Brazil (Santa Catarina and São Paulo) ( Fig. 51 ). Syneches digitatus sp. nov. is known to occur only in the Atlantic Forest biome.

Variation. Scutellar bristles may vary from 3–4. Hind femur with a median dark yellow spot; hind femur with 3–5AD bristles on apical half.

Remarks. The new species is similar to S. amazonicus by the brown scutum, narrower than mesopleuron, but differing from it by the brown antennae with postpedicel wholly yellow, hind femur strongly swollen bearing spiniform bristles inserted on short tubercles and distal margin of hypandrium with 2 short digitiform projections (see also “Remarks” under S. amazonicus ).

Etymology. From the Latin digitus = finger; specific epithet refers to the two short digitiform projections on the distal margin of the hypandrium.

Figures

FIGURE 16. Syneches digitatus sp. nov. 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.

FIGURE 17. Syneches digitatus sp. nov. A–D. Male terminalia (paratype from type-locality). A. Epandrium and hypandrium, phallus and postgonite darkened, ventral view; B. Epandrium with cerci, dorsal view; C. Left epandrial lamella with cercus, lateral view; D. Distal margin of hypandrium, apex of phallus and postgonite, ventral view. E–F. Female terminalia (paratype from type-locality) in dorsal and ventral views respectively. Scale bars = 0.1 mm.

FIGURE 51. Syneches Walker. Geographical records of S. amorimi sp. nov.; S. barrettoi sp. nov.; S. catarinae Smith, 1962 and S. digitatus sp. nov. in Brazil.