Poecilominettia erebus Soares & Gaimari, 2024

Soares, Matheus M. M., Gaimari, Stephen D., Corrêa-Neto, José De J., Limeira-De-Oliveira, Francisco & Rafael, José A., 2024, Insect (Hexapoda) diversity in the oceanic archipelago of Fernando de Noronha, Brazil: Lauxaniidae (Diptera), Zootaxa 5537 (1), pp. 1-23 : 11-15

Poecilominettia erebus Soares & Gaimari sp. nov.

( Figs. 5 , 6 )

Poecilominettia sp. 1 ( Rafael et al. 2020).

Diagnosis. Differs from the other congeneric species by the combination of the body being mostly homogeneously brown to orangish brown, and lacking spot or stripe patterns ( Fig. 5A, B ), with the pleuron being distinctly darker than the scutum; wing hyaline; femora wholly brownish ( Fig. 5A, B ); and surstylus short, somewhat comma-shaped in posterior view ( Fig. 6A ) and subtriangular in lateral view ( Fig. 6B ).

Description. Head ( Figs 5A–E ). Mostly brown to orangish brown, frons with two narrow central brown stripes, extended from the anterior margin to the ocellar triangle; face darkened medially, orange in lower corners and paler brown medially; parafacial dark brown, with silvery pruinosity. Head 1.3X higher than long, 1.3X wider than high, 1.1X wider than scutum; eye 1.1X higher than long; gena height (directly below eye) 0.1X eye height. Vertex orange pruinose, rounded; inner vertical seta long and strong, about 1.6X longer than outer vertical seta, with distance between them about 1/2 that from inner vertical seta to central vertex. Ocellar triangle small, slightly raised, placed slightly in front of vertex, and in front of level of inner vertical seta; ocelli subequal in size and disposed in small equilateral triangle, covered with few tiny setulae. Ocellar setae proclinate and divergent, small and weak. Postocellar setae convergent to cruciate, about 2X longer than ocellar seta. Two rows of short postocular setulae. Median occipital sclerite silvery pruinose and with supracervical setae above occipital foramen. Frons about as long as wide, frons arched, curved evenly into facial plane; with 2 strong reclinate fronto-orbital setae, posterior seta slightly longer than anterior seta, and located at midpoint between inner vertical seta and anterior seta, with anterior seta located at midpoint between posterior seta and lunule; frons setulose on anterior 1/2, and with few sparse setulae at posterior 1/2, almost wholly bronzy pruinose, except region between anterior and posterior fronto-orbital setae and around the ocellar triangle silvery pruinose, and a paler strip from the ocellar triangle to the lunule. Lunule low, straight. Antenna mostly dark orange, except apical 2/3 of arista dark brown; scape with few short dorsal setae; pedicel with 1 long dorsal seta at middle length, with crown of short setae at apex and 2–3 long ventral setae; first flagellomere about 1.5X longer than high, and about 2.5X longer than scape and pedicel combined, with rounded apex; arista inserted dorsobasally on first flagellomere, covered with short microtrichia. Gena with row of strong setae at ventral edge, extended onto lower parafacial; postgena orange, with rows of short, strong setae. Face about 1.2X wider than long, dark brown, except lower corners orangish and central part paler brown; parafacial dark brown, with silvery pruinosity. Clypeus orange, narrow. Maxillary palpus and labellum dark orange, ventral surface of maxillary palpus with rows of long setae.

Thorax ( Fig. 5A, B, E, H ). Scutum slightly arched, 1.2X longer than wide; scutellum about 1/3 as long as scutum, with width at base about 2X greater than length; scutum mostly brown, with postpronotum pale yellow; scutellum pale brown, apical margin pale yellow between dark brown spots at bases of posterior scutellar setae ( Fig. 5H, I ); pleural region mostly dark brown ( Fig. 5A, B ). Chaetotaxy: 0+3 dorsocentral setae, anterior seta slightly shorter than middle seta, located at midpoint between transverse suture and middle seta, middle seta located at midpoint between posterior seta and anterior seta; posterior seta located closer to scutellar suture than to middle seta prescutellar acrostichal seta present, strong; 1 postpronotal seta; 2 notopleural setae, in anterior and posterior corners, anterior seta slightly longer than posterior; postsutural intra-alar seta present; 1 presutural and 1 postsutural supra-alar setae; 2 postalar setae, in anterior and posterior corners; 6 irregular rows of acrostichal setulae between dorsocentral setal rows, row of setulae along dorsocentral area present, and setulose outside dorsocentral row; proepisternal seta present, strong; anepisternum with anepisternal seta along posterior edge, otherwise setulose in posterior 2/3; anepimeron bare; 2 katepisternal setae present, both strong, anterior one slightly stronger than posterior, katepisternum otherwise setulose in anterior half, and with group of long ventral setae close to the coxa; 2 pairs scutellar setae, anterior setae subparallel, posterior setae convergent or cruciate. Legs ( Fig. 5A, B ). Mostly yellow, except all coxae and femora brown. Fore femur with 5 posteroventral long and strong setae in apical 2/3, about 1.5X longer than width of femur, posterior row of slender setae from base to apex and posterodorsal row of long and strong setae from base to apex; ctenidium absent. Mid femur with anterior row of short and strong setae in apical 1/2, and with 1 short curved posteroventral preapical seta. Hind femur with anteroventral row of short setae in apical 1/3 and 1 anterodorsal long preapical seta. All tibiae with preapical dorsal seta, strongest on mid tibia; mid tibia with 1 longer preapical ventral seta, as long as dorsal seta; hind tibia with 1 short apical ventral spur. Wing ( Fig. 5F ). Hyaline, veins orangish to pale brown. Length 3.4 mm; 2.6X longer than high. Cell dm about 4X longer than crossvein dm-m. Crossvein r-m located at midpoint of cell dm. Vein R 4+5 ending at wing tip, subparallel with veins R 2+3 and M 1. Crossvein dm-m straight, located slightly basal to midpoint between crossvein r-m and tip of vein M 1. Vein M 4 about 0.4X as long as crossvein dm-m. Vein CuA+CuP short, about 1/2 as long as vein A 1.

Abdomen ( Fig. 5A ). Tapered gradually after segment 4; homogeneously orangish yellow. Tergites covered with short setulae, longest and strongest along posterior edges of syntergite 1+2 and tergites 3–6. Sternites pale yellow to white, sternite 1 bare, sternites 2–5 setulose, with slightly longer setae at lateral margins; sternites 2–5 each slightly wider than long, subequal in width sternite to sternite; sternite 6 as a membranous transverse strip. Male genitalia ( Fig. 5G , 6A–D ). Pale yellow, except epandrium with dorsal rectangular dark brown spot ( Fig. 6A ). Syntergosternite 7+8 simple, bare, transversely saddle-shaped. Epandrium simple, saddle-shaped, length and width subequal; setulose, with long setae in posterior 1/2 ( Fig. 6A, B ). Surstylus broadly comma-shaped in dorsal view, with apex incurved to pointed and darkened apex ( Fig. 6A, B ), with long setae on posterior 1/2; subtriangular in lateral view. Subepandrial sclerite short, about 2X longer than wide. Cercus short, ovoid, heavily setose ( Fig. 6A, B ). Ejaculatory apodeme long and narrow, weakly sclerotized anteriorly ( Fig. 6C ). Basiphallus somewhat tubular, weakly sclerotized at apex and covering the distiphallus, about 2X longer than wide; apex of distiphallus with short, sclerotized teeth and 5 long teeth, about 1/2 as long as basiphallus ( Fig. 6C, D ). Hypandrium as a narrow transverse band. Postgonite wide basally, posteriorly with 1 short and acute projection, anteriorly long and narrow, digitiform, with 1 short subapical seta ( Fig. 6C, D ).

Female: Similar to male ( Fig. 5B ), except tergites 4–6 with narrow median stripe, and lateral portions of syntergite 1+2 and tergites 3–5 dark brown ( Fig. 5H, I ). Female terminalia ( Fig. 5I , 6E–H ). Tergite 7 not fused to sternite 7. Tergite 8 membranous, with row of long setae at posterior edge ( Fig. 6E, F ). Sternite 8 almost divided into two subtriangular dark brown hemitergites, posterior edge with row of short setae ( Fig. 6G ). Epiproct semicircular, setulose ( Fig. 6E, F ). Hypoproct simple, semicircular, setulose ( Fig. 6E, G ). Spermathecae round, with configuration 1+2, paired spermathecae, surface smooth ( Fig. 6H ).

Type material examined. Holotype ♂ ( INPA), double mounted, in good condition, not dissected, with following data: “ BRASIL, PE [Pernambuco], Fernando de / Noronha , 3°51′17″S –/ 32°26′26″W, Capim-Açu”, “ 11–27.xi.2019, Malaise trap / G[grande], J.A. Rafael, F. Limeira- / de-Oliveira, L.C. Castro ” . PARATYPES. BRAZIL. Pernambuco, Fernando de Noronha: Capim-Açu , 03°51′17″S – 32°26′26″W, 09–24.vi.2019, large Malaise trap, J.A. Rafael, F. Limeira-de-Oliveira & L.C. Castro (8 ♀, INPA) ; same data, except 08–25.ix.2019 (1 ♂, 12 ♀, CZMA; 1 ♂, 5 ♀, SDG) ; same data, except 25.ix–8.x.2019 (1 ♂, 5 ♀, AMNH; 1 ♂, 8 ♀, MNRJ) ; same data, except 08–27.x.2019 (1 ♂, 5 ♀, CSCA; 1 ♂, 13 ♀, MZUSP) ; same data, except 27.x–11.xi.2019 (10 ♀, AMNH; 10 ♀, CSCA; 10 ♀, CZMA; 19 ♀, INPA; 10 ♀, MNRJ; 10 ♀, MZUSP; 1 ♂, 5 ♀, USNM) ; same data, except 11–27.xi.2019 [same data as holotype] (5 ♂, 2 dissected, 3 ♀, 2 dissected, INPA) ; same data, except 27.xi–9.xii.2019 (17 ♀, INPA) ; Sancho , 03º51′17″S – 32°26′26″W, 09–24.vi.2019, Malaise trap, J.A. Rafael, F.L. de Oiveira, L.C. Castro (21 ♀, INPA; 5 ♀, SDG) ; same data, except 24.vi–8.vii.2019, large Malaise trap (5 ♀, AMNH; 3 ♀, CSCA; 3 ♀, USNM; 3 ♀, SDG) ; same data, except 27.x–11.xi.2019 (1 ♀, INPA) ; same data, except 9–27.xii.2019 (4 ♀, AMNH; 5 ♀, CSCA; 4 ♀, USNM; 4 ♀, SDG) ; same data, except 23.i–12.ii.2020 (19 ♀, INPA; 5 ♀, USNM) ; Trilha Sancho , 3°51′30″S – 32°25′50″W, 01–09.vi.2019, Malaise trap, J.A. Rafael, F. Limeira-de-Oliveira & D.M.M. Mendes [=same data as holotype] (27 ♀, INPA) ; same data, except armadilha luminosa [light trap] (1 ♀, INPA) ; same data, except 09–24.vi.2019 (1 ♂, dissected, INPA) ; same data, except 24.vi–08.vii.2019, J.A. Rafael, F. Limeira-de-Oliveira & L.C. Castro (1 ♀, dissected, INPA) ; same data, except 09–27.xii.2019 (1 ♂, dissected, INPA) ; same data, except 11–27.ii.2020, J.A. Rafael, F. Limeira-de-Oliveira & P.C. Grossi (2 ♀, INPA) .

Additional material examined. 131 specimens from nearly all localities in ethanol.

Remarks. Using the key of Broadhead (1989), this species runs to couplet 34 and to Po. grata (Wiedemann, 1830) . However, it is clearly not this species by comparison with the type, which is a wholly yellow species, with the pleuron not darkened and the female terminalia lacking paired dark patches. The new species is far more similar to Po. brunneicosta ( Malloch, 1928) , which is immediately different from the new species in having a distinctly darkened posterior 1/3 of the wing (through cells sc, c, r 1, r 2+3). The new species also differs from Po. brunneicosta in that the latter species lacks brown patches at the bases of the posterior scutellar setae, the parafacial and the face are yellow, and the surstylus is of a different shape. Poecilominettia erebus sp. nov. was the third more abundant species in Fernando de Noronha with 409 specimens, representing 2.2% of the specimens collected throughout the nine months using interception traps.

Distribution. The new species is known only from the oceanic Archipelago of Fernando de Noronha, Pernambuco, Brazil.

Etymology. A noun in apposition, from Greek mythology, the god Erebus is the personification of darkness, in reference to the dark color of this species.

Figures

FIGURE 5. Poecilominettia erebus Soares & Gaimari, sp. nov. A, C–H male holotype (INPA), B, I, J female paratype (INPA). A, B. Habitus, lateral view; C, D. Head, anterior and lateral views, respectively; E. Head and thorax, dorsal view; F. Wing; G. Male terminalia, posterior view; H. Male scutellum, posterior view. Abbreviations: afrs = anterior fronto-orbital seta; ep spt = spot on epandrium; ialp s = postsutural intra-alar seta; kpt s = katepisternal seta; flgm 1 = first flagellomere; ot = ocellar triangle; sctl spt = spot on scutellum.

FIGURE 6. Poecilominettia erebus Soares & Gaimari sp. nov. A–D male paratype (INPA), E–H female paratype (INPA). A, B. Epandrium in posterior and lateral views, respectively; C, D. Internal appendages in lateral and anterior views, respectively; E–G. Female terminalia in lateral, dorsal and ventral views, respectively; H. Spermathecae. Abbreviations: bp = basiphallus; cerc = cercus; dp = distiphallus; e = epiproct; epand = epandrium; h = hypoproct; hypd = hypandrium; ej apod = ejaculatory apodeme; te = teeth of distiphallus; st = sternite; tg = tergite; pgt = postgonite; sur = surstylus.