Syneches exilis, Menezes, Isis Sá & Ale-Rocha, Rosaly, 2016

Menezes, Isis Sá & Ale-Rocha, Rosaly, 2016, Revision of the Amazonian species of Syneches Walker (Diptera, Hybotidae, Hybotinae), Zootaxa 4103 (5), pp. 401-442 : 417-419

Syneches exilis sp. nov.

( Figs 47–53 , 109 , 119 )

Diagnosis. Antenna brown; postpedicel with 1 long dorsal medial seta, longer than postpedicel; palpus brown, half of proboscis length, with 2 long setae. Scutum high and rounded, dark brown; pleura dark brown except for posterior half of anepimeron, posterior margin of katepisternum, anterior margin of meron and metapleuron light brown; scutellum with four pairs of lateral setae, apical pair absent. Legs long and slender; light brown except basal half of fore tibia, fore and mid tarsomeres 3–5, hind femur, hind tibia and tarsomeres brown; mid tibia with 3 long AD setae. Wing sub-hyaline, darkened at costal region up to the apex; apex of R2+3 almost straight; pterostigma brown, elongate.

Description. Holotype ♂. Body: 4.0 mm. Wing: 3.6 mm. Head. Eyes with lower facets larger around buccal opening. Ocellar triangle protuberant with golden pruinescence. Face brown with reddish brown pruinescence. Antenna brown with short reddish brown setulae; pedicel rounded, brown marginal setae long, equal in length or longer than postpedicel; postpedicel small, as long as combined length of scape and pedicel, ovate-elongate, 1.3 times longer than wide, with 1 long dorsal medial brown seta, longer than antenna; stylus about 3.5 times length of antenna, with short setulae, bare at 1/4 distal. Postcranium with reddish brown pruinescence. Proboscis light brown with darker base; palpus brown, half of proboscis length, setulae reddish brown, 1 apical and 1 long ventral medial seta. Thorax. Prosternum narrow. Pronotum dark brown, with golden pruinescence and brown elongate marginal setae. Scutum high and rounded, dark brown, with rough reddish brown pruinescence, posterior margin of postpronotal lobe and postalar callus light brown; setae sparse, brown and long, longer on prescutellar disc; 4 series of acrostichal setae and 1 dorsocentral series; scutellum dark brown, lighter basally, with reddish brown pruinescence. Pleura dark brown except for posterior half of anepimeron, posterior margin of katepisternum, anterior margin of meron and metapleuron light brown, with golden pruinescence. Chaetotaxy: 1 dc and 1 acr, long and robust, with apices bent ventrally, on prescutellar disc; 2 long and robust npl, widely separated, posterior seta longer; 3 pal, posterior longer and stronger; scutellum with 1 long, robust subapical pair and 3 weak lateral setae about 1/3 length of subapical pair; apical pair absent. Legs. Long and slender. Coxae, trochanters, fore femur, mid femur and tibia, apical half of fore tibia, fore and mid tarsomeres 1–2 light brown; basal half of fore tibia slightly darker; hind femur, tibia and tarsomeres, and fore and mid tarsomeres 3–5 brown. Fore tibia with D row of long setae, preapical seta stronger; 4 long PV, one sub-basal, equal in length to tarsomere 1, one median and 2 preapical setae, apical most seta shorter. Fore tarsomere 1 with 1 PD and 1 preapical D; PV row of setae larger on basal half; row of more stout setae ventrally. Mid femur with AV and PV rows of longer and stronger setae at basal half. Mid tibia with 1 PD before middle and 1 PD preapical seta; one sub-basal, one before middle equal in length to tibia and one preapical long and strong AD seta; PV surface with one median almost reaching apex of tibia, one preapical and one apical larger than half-length of tarsomere 1; AV surface with one median seta equal in length to tibia, one preapical and one apical very long seta; 1 V short and robust apical seta. Mid tarsomere 1 with 1 D preapical seta. Hind femur with 4 AD and 4 PD slightly long and strong setae on distal half; 1 AV median and 1 AV preapical. Hind tibia with 4 D setae; 1 A apical; 1 PD preapical; V surface with 1 median, 1 preapical and 1 apical seta; 1 apical AV. Hind tarsomere 1 with 5 A spine-like and 5 D long setae. Wing ( Fig. 109 ). Sub-hyaline with tenuous light brown infuscation at costal region up to apex; apex of R2+3 almost straight; pterostigma brown, narrow and elongate, five times longer than wide. Abdomen. About 3.5 times length of thorax. Dark brown with rough and reddish brown pruinescence. Setae brown, long, slightly stronger on laterodistal margin of tergites. Tergite 8 short, 3.5 times wider than long ( Fig. 50 ); sternite 8 trapezoidal, narrowed basally ( Fig. 51 ). Terminalia ( Figs 47–49 ): elongate; hypandrium long, two times longer than wide, slightly narrowed distally with rounded apex and pair of moderately long setae reaching over apex of phallus; epandrium long, epandrial lamella wide basally and slender on distal 1/ 3 in lateral view, with long setae; phallus short with two lateral tubercles, one long apical and one shorter preapical, both strongly sclerotized; postgonite simple, wide, as long as phallus. Female. Similar to male except as follow: Terminalia ( Figs 52, 53 ): elongate, sternite 8 narrowed towards base (cercus damaged).

Type material. HOLOTYPE ♂ ( USNM): VENEZUELA, T.P.A. Basecamp, 0°51'N – 66°10'W, Cerro da Neblina, 140m, 20–24.iii.1984, O. Flint & J. Louton / Malaise trap over small stream at east side of basecamp / Holótipo, Syneches exilis, Menezes & Ale-Rocha (red label). Condition of holotype: good, terminalia dissected. PARATYPES: BRASIL. Amazonas, S[anta]. Izabel [do] R[io]. Negro, Maturacá, 11–16.x.1990, Arm[adilha]. Malaise, J.A. Rafael (3 ♂, 1 ♀, INPA).

Geographical distribution. Venezuela, Brazil (Amazonas) ( Fig. 119 ).

Comment. This species is similar to S. longiflagellatus in having a long abdomen and slender legs, but it can be distinguish from it by the narrow prosternum, high scutum and elongate pterostigma (wide prosternum, scutum moderately high and small rectangular pterostigma in S. longiflagellatus ).

Etymology. From the Latin exilis = slender, thin, slim, in reference to the appearance of the legs and abdomen.

Figures

FIGURE 119. Geographical distribution of S. curvipes, S. dichrous, S. equatoriensis, S. exilis, S. fuscescens and S. jauensis in Amazon.

FIGURES 47 – 53. Syneches exilis sp. nov. (paratype). Male terminalia: 47, epandrium, cerci and hypoproct (dorsal view); 48, hypandrium, postgonite and phallus (ventral view); 49, right epandrial lamella (vista lateral); 50, tergite 8; 51, sternite 8. Female terminalia: 52, ventral view; 53, dorsal view. Scale = 0.2 mm.

FIGURES 103 – 117. Wings of Amazonian species of Syneches: 103, S. amazonicus sp. nov.; 104, S. angulatus sp. nov.; 105, S. applanatus sp. nov.; 106, S. bilobatus sp. nov.; 107, S. curvipes; 108, S. equatoriensis sp. nov.; 109, S. exilis sp. nov.; 110, S. maculosum sp. nov.; 111, S. manaos; 112, S. moraballi; 113, S. striatus sp. nov.; 114, S. tenebricus sp. nov.; 115, S. walkeri; 116, S. sp. 1; 117, S. sp. 2. Scale = 0.5 mm.