Scelolabes amorimi Barros & Freitas-Silva & Ale-Rocha 2023, sp. nov.

Scelolabes amorimi sp. nov.

urn:lsid:zoobank.org:act: CFF43F85-0A48-464B-9733-EB4FA56BA9D3

Figs 1–2, 7A

Diagnosis

Scape and pedicel yellow, postpedicel brown (Fig. 1D). Scutum extensively black, except for narrow yellow triangular marks on anterior and posterior acrostichal region (Fig. 1F). Pleura (Fig. 1A) yellow, except entire anepisternum and brown spots on upper margin of katepisternum, on anterior margin of anepimeron and on upper margin of meron. Legs (Fig. 1A) whitish yellow, except apical half of hind femur light brown.

Etymology

The epithet amorimi is named after the dipterologist Dalton Amorim, for having collected the holotype and part of the paratype series.

Type material

Holotype CHILE • ♂ (good condition, except by the right hind leg lost); “ Osorno, Pq. Nac. [Parque Nacional] Puyehue, Termas Aguas Calientes, 40°44′S / 72°19′W, 440 m, 14–31. i. 2017, sweeping, V. C. Silva & D. S. Amorim [white label]”, “ HOLOTYPE, Scelolabes amorimi Barros, Freitas-Silva & Ale-Rocha ” [red label]; MNHN.

Paratypes CHILE • 1 ♂, 10 ♀♀; same collection data as for holotype; INPA • 1 ♂, 10 ♀♀; same collection data as for holotype; MNHN • 10 ♀♀; same collection data as for holotype; MNRJ • 8 ♀♀; same collection data as for holotype; MZUSP • 5 ♀♀; same collection data as for holotype except “ 464 m, 40°44′16″ S, 72°18′24″W, 14.i–3.ii.2017, Shannon Trap, D.S. Amorim & V.C. Silva cols”; MNHN • 1 ♂, 14 ♀♀; same collection data as for holotype; INPA • 1 ♂, 10 ♀♀; same collection data as for holotype; MNHN • 14 ♀♀; same collection data as for holotype; MZUSP • 5 ♀♀; same collection data as for holotype except “ 464 m, 40°44′16″ S, 72°18′24″W, 14.i–3.ii.2017, Shannon Trap, D.S. Amorim & V.C. Silva cols”; MNHN • 1 ♀; “ 10 km E of Puyehue, 26.i.1951, leg. Ross & Michelbacher ”; CAS • 1 ♀; “ Puerto Fuy, Valdivia, 4.iii.1955, L.E. Peña ”; CNC • 1 ♂; “R.[Region] IX, PN [Parque Nacional] Nahuelbuta, 37°48′58″S, 73°00′36″W, 9–10.ii.2005, YPT [Yellow Pan Trap], mature Nothofagus for., L. Masner, UCR A tol”; CNC.

Description

Male (Fig. 1A, C–D, F, H).

MEASUREMENTS. Body length: 4.5 mm. Wing length: 4.3 mm.

HEAD. Dichoptic, frons shining brown, narrow, about same width of anterior ocellus. Face narrower than frons, about 1.8 × length of frons. Antenna (Fig. 1D) yellow, except postpedicel brown, scape as long as pedicel, postpedicel lanceolate, about 2× length of scape and pedicel combined, with dense brown microtrichia; stylus about 1.7× length of antenna. Proboscis whitish yellow and short; palpus whitish yellow, short, oval, covered with dense yellow pruinosity and 1 long slender seta. Two pairs of proclinate ocellar setae, anterior pair longer and stronger, posterior very short and slender. Occiput (Fig. 1E) black covered with dense grey pruinosity, postocular setae elongated, scattered, upper postocular setae stronger. THORAX. Shining. Pronotum brown with grey pruinosity. Scutum (Fig. 1F) longer than wide, black, except for orange yellow subtriangular acrostichal area on anterior fourth and triangular spot on the prescutelar region, middle of acrostichal region paler, postpronotal lobe and postalar callus yellow. Pleura (Fig. 1A) whitish yellow, except anepisternum, brown spots on upper margin of katepisternum, on anterior margin of anepimeron and on upper margin of meron. Scutellum brown, paler on apical margin, short lateral scutellar seta thin and short, apical scutellar bristle yellow, long and strong; mediotergite brown with grey pruinosity. Acrostichal setae 4-serial, dorsocentral setulae uniserial, short, slender and sparse on scutum, posterior dorsocentral seta longer; several short and slender setae in the prescutelar region; several short and slender postpronotal setae; notopleuron with light grey pruinosity, 1 long and strong bristle and several shorter, thin setae; 2 postalar setae, 1 anterior long and strong, 1 posterior short and thin.

WING (Fig. 1G). Membrane pale brown; pterostigma brown, elongate and narrow; dm cell shorter than basal cells, approximately 3× as long as wide; bm cell 1.3× length of cell cua; CuA vein incomplete, not reaching CuP vein. Halter (Fig. 1C) whitish yellow, stem with a row of spine-like setulae.

LEGS (Fig. 1A). Whitish yellow, except apical half of hind femur light brown. All coxae subequally long. Legs long and slender, except apex of hind femur and hind tibia slightly swollen. Chaetotaxy: fore femur with 1 long and slender anterodorsal sub-basal seta, 1 anterodorsal and 1 posterodorsal setae at apical ⅓; mid femur with 1 strong anterodorsal seta at basal ⅓, 2 strong posterodorsal on apical half and 1 strong anterodorsal subapical setae; hind femur with 1 strong anterodorsal sub-basal, 1 strong posterodorsal sub-basal, 1 strong anterodorsal subapical, 1 anteroventral row of strong setae on apical half and a posteroventral row of long setae, last strong, both inserted on short tubercles. Fore tibia without outstanding setae; mid tibia with 2 slender basal setae, 1 anterodorsal and 1 posterodorsal, 1 strong anterodorsal seta at mid-length, 1 strong anterodorsal seta at apex, 1 strong anteroventral and 1 strong posteroventral apical setae; hind tibia with 1 slender dorsal basal seta, 2 posterodorsal apical setae, 1 slender and 1 strong, 1 strong anteroventral apical seta. Tarsi without outstanding bristles.

ABDOMEN (Fig. 1H). All tergites brown, whitish and weakly sclerotized anteriorly. Sternites 1–4 weakly sclerotized, hyaline; sternites 5–8 pale brown, weakly sclerotized anteriorly. All tergites with long and slender setae on apical margin.

MALE TERMINALIA (Fig. 2A–F). Hypandrium (Fig. 2A) short, sub-quadrangular, as long as wide, with a short projection with an apical tuft of long and slender setae on right side. Epandrial lamellae covered with several short and slender setae. Left epandrial lamella (Fig. 2C) subtriangular, shorter than right, as wide as long; right epandrial lamella (Fig. 2D) broad, sub-quadrangular, as wide as long, dorsobasal pointed projection short and wide. Left surstylus (Fig. 2E) long, slightly sharpened, curved at apex, turned direct to dorsal margin, with 1 row of long and slender setae close together on dorsal surface, 1 row of long, slender and scattered setae on ventral surface, all setae inserted on tiny tubercles; right surstylus (Fig. 2F) shorter, about ⅔ length of left surstylus, left lobe thin, sharpened and claw-like, longer than right, right lobe rounded with short and slender setae, dorsal surface near base with a row of long, slender and scattered setae, inserted on tiny tubercles. Cerci (Fig. 2B) symmetrical, short, subtriangular, weakly sclerotized, covered with short and slender setae. Subepandrial sclerite (Fig. 2B) with basal and apical margins truncate. Hypoproct (Fig. 2B) sub-quadrangular, with a small triangular projection in left margin, behind left cercus. Bacilliform sclerite asymmetrical with short and slender setae.

Female (Fig. 1B)

Similar to male, except by abdominal tergites entirely sclerotized.

FEMALE TERMINALIA (Fig. 2G). Tergite and sternite 8 laterally fused, broad. Sternite 8 with slight and short constriction in posterior margin shaping a bifid and sharpened projection, covered by several short and slender setae. Tergite 10 absent. Sternite 10 slightly sclerotised, small, sub-triangular, with a narrow mediobasal division until ⅓ of length, covered with several short and slender setae. Cerci slightly sclerotised, flattened, short, about ⅔ of sternite 10, covered with several short and slender setae.

Variation

Some specimens may have the scutum with full yellow acrostichal stripe, probably due to preservation in alcohol.

Remarks

The female terminalia of S. amorimi sp. nov. are different from those of S. bivittatus by the sternite 10 narrowly divided mediobasally until ⅓ of length, whereas those of S. bivittatus are divided medially until half the length of sternite 10. The scutum of S. amorimi is clearly darker than in the other two species of the genus, with only narrow triangular yellow marks on the anterior and posterior part of the acrostichal area. The brown mark on the pleura is also more extensive in S. amorimi than in S. bivittatus and S. verasilvae sp. nov.

Distribution

This species is known only from Chile (Osorno; Fig. 7A).