Microcerella obscura, Santos & Mello-Patiu & Couri & Mulieri, 2025

Microcerella obscura sp. nov.

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Figs 1–2 View Fig View Fig

Diagnosis

Male: head without proclinate orbital setae; wings with vein R 1 setulose; terminalia with epandrium orange ( Fig. 2D View Fig ), basiphallus and distiphallus distinctly separated by a dorsal membranous strip ( Fig. 1C View Fig ), and vesica with a superior and inferior projection, the inferior one with a serrated margin ( Fig. 1C–D View Fig ).

Etymology

The species epithet ‘ obscura ’, from Latin and treated as an adjective, refers to the dark phallic structures.

Type material

Holotype ARGENTINA • ♂, terminalia dissected and stored in a microvial with glycerin; “Argentina:Pr. [Province] Catamarca / Cuesta Minas Capillitas / 3000m Pastizal J.L.Neff / #refers to host & date. [printed on white paper] // 84573 [printed on white paper] // Collection of the / CALIFORNIA ACADEMY / OF SCIENCES San / Francisco Calif. [printed on white paper] // Microcerella / sp. / T. Pape det. 1987 [handwritten, with T. Pape det. printed] // HOLOTYPE [printed on red paper] // Microcerella obscura sp. nov. / Santos, Mello-Patiu, / Couri & Mulieri 2025” [handwritten on white paper] // CASENT / 8451106 [printed on white paper]”; CASENT8451106 ; CAS.

Description

Male (n = 1)

MEASUREMENTS. Length: 9 mm.

HEAD. Parafacial, fronto-orbital plate and postocular orbit dark brown with silver pruinosity ( Fig. 2A– C View Fig ); facial ridge with few setae on lower ¼; parafacial with row of setulae close to eye, similar in size to subvibrissal setae; frons about 0.27 × head width at level of ocellar triangle; frontal vitta blackish ( Fig. 2B–C View Fig ); 7–9 well-developed frontal setae reaching level of apex of pedicel; rows of frontal setae parallel except anteriormost 3 divergent; reclinate orbital seta present, proclinate orbital setae absent; ocellar setae as developed as upper frontals; [outer vertical seta broken]; gena and genal groove with silvery pruinosity ( Fig. 2A, C View Fig ); gena with black setae; postgena silvery-gray pruinose with black setae; antenna black ( Fig. 2A, C View Fig ); first flagellomere approximately 1.5 ×as long as pedicel; arista short pubescent on basal half ( Fig. 2C View Fig ); palpus blackish ( Fig. 2A, C View Fig ).

THORAX. Dark brown with silver pruinosity ( Fig. 2A–B View Fig ); chaetotaxy: acrostichals 0 +? [pin inserted in the middle], dorsocentrals 2+3, intra-alars 1+2, supra-alars 1+3, postpronotals 3, notopleurals 4; postalar wall bare; postalar callus with 2 setae; scutellum with pair of basal and pair of subapical setae, pair of discal setae and without apical setae; katepisternum with 3 setae almost in straight line; meral setae 5; proepisternum bare.

WING. Hyaline, with dark brown veins ( Fig. 2A–B View Fig ); tegula dark brown; basicosta yellowish; vein R 4+5 with setulae dorsally at basal ⅔ of distance to crossvein r-m; vein R 1 setulose; cell r 4+5 open at wing margin; costal spine differentiated; third costal sector bare ventrally.

LEGS. Blackish-brown, pulvilli yellowish-brown ( Fig. 2A View Fig ); mid femur with 2 median anterior setae, row of anteroventral setae, 2 preapical posterior setae, row of posteroventral setae, and without ctenidium; mid tibia with 2 median anterior setae, 2 median posterior setae and 2 posterior setae in apical third; hind trochanter without ventromedian pad of short, spiniform setae.

ABDOMEN. Dark brown with silvery-gray pruinosity and slightly yellowish pruinosity laterally ( Fig. 2A View Fig ); T4 with pair of median marginal setae and pair of lateral marginal setae; T5 with row of marginal setae; ST2–4 with marginal setae slightly more developed than discal setae; ST5 with membranous window, arms approximately 2.5 × of base length, and dense setae pattern.

TERMINALIA. Syntergosternite 7+8 and apex of phallus black, other structures orange ( Fig. 2D View Fig ); cercus with numerous long setae in basal half and short and sparse setae in apical half; cercal prongs divergent dorsally and rounded ( Fig. 1A–B View Fig ); surstylus clavate, with long apical setae ( Fig. 1B View Fig ); pregonite straight, almost same length as postgonite ( Fig. 1C View Fig ); postgonite with apex pointed and curved and a short seta inserted on anterior margin near base ( Fig. 1C View Fig ); postgonal apodeme short and rectangular ( Fig. 1C View Fig ); basiphallus and distiphallus distinctly separated by dorsal membranous strip ( Fig. 1C View Fig ); paraphallus with ventro-apical projection ( Fig. 1C View Fig ); vesica with superior and an inferior projection, inferior one with serrated margin ( Fig. 1C–D View Fig ); juxta distinctly separated from paraphallus ( Fig. 1C–D View Fig ); acrophallus formed by median stylus, median process, and pair of lateral styli ( Fig. 1C–D View Fig ); median stylus almost straight, median process tubular and lateral stylus curved ( Fig. 1C–D View Fig ).

Female

Unknown.

Remarks

Microcerella obscura sp. nov. is morphologically similar to M. austrohartigia Pape, 1990 , and M. multidentata ( Lopes, 1981) . These three species can be separated by the configuration of the serrated margin of the inferior projection of the vesica, which in M. obscura has different-sized serrations and is inserted almost in a straight line ( Fig. 1C–D View Fig ), in M. multidentata it also has different-sized serrations but is inserted in a pointed projection ( Lopes 1981: figs 60–61), and in M. austrohartigia it has similar-sized serrations and is inserted almost in a straight line ( Lopes 1981: figs 46–49).

Distribution

Argentina (Catamarca).