Marbenia peculiaris Malloch

Ale-Rocha, Rosaly, Freitas, Geovânia & Mathis, Wayne N., 2014, Revision of the Neotropical genus Marbenia Malloch (Diptera: Periscelididae), Zootaxa 3872 (4), pp. 365-375 : 372-374

Marbenia peculiaris Malloch

( Figs 16–23 )

Marbenia peculiaris Malloch, 1931: 32 , Figs. 9, 10 ; Prado, 1975: 1 –3 (Neotropical catalog); Mathis & Rung, 2011: 352 (world catalog).

Diagnosis. Frons with central portion shiny dark yellow to brown and lateral margins pale yellow to yellow with whitish pruinescence; first flagellomere orange; ocellar tubercle the same color of frons; face brown to pale brown with yellow spots and transverse furrows on medial portion, not protruded; wing gray to brown tinged with 1 transverse narrow hyaline band on middle of distal third, 1 small hyaline spot on crossvein r-m and cell R2+3, and hyaline on basal third; scutum dark brown with postpronotal lobe and postalar callus yellow, covered by silvery gray pruinescence; scutellum yellow.

Redescription. Holotype female. Body: 3.5 mm. Wing: 2.75 mm. Head ( Figs 17, 18 ). Frons dark yellow, including ocellar triangle, shiny, with lateral margin pale yellow with whitish pruinescence. Ocellar triangle not protuberant, ocelli yellow forming an equilateral triangle. Medial and lateral vertical setae and fronto-orbital seta the same length; post-ocellar setae developed and divergent (ocellar pair lost in the specimen). Face with sparse whitish pruinescence according to incidence of light, slender than frons, with one small inverted dark yellow triangle below the antenna, median portion pale yellow and the remaining pale brown. Setae: lower fronto-orbital plate with short brown setae extended from fronto-orbital setae to insertion of antenna; a pair of convergent pseudo-vibrissae developed, inserted on medial portion of face, half length of face; parafacial setae well developed, extended from mid length of face, shorter on upper portion and increasing in length toward buccal opening; face with transverse shallow furrows three of which deeper, one on dorsal third, one medial and one on basal third, giving a wavy appearance to face. Parafacial pale brown with whitish pruinescence; gena yellow with narrow band whitish pruinescence around eye margin; gena short and wholly setulose. Antenna: scape very short, whitish; pedicel velvet black with some short dorsal and marginal setae; first flagellomere orange, ovate, about 3 times longer than wide; arista bipectinate, with 13 dorsal and 4 ventral branches with some interspersed very short branches. Buccal structures pale brown; labrum small with whitish pruinescence; palpus short, ovate, setulose. Occiput and postgena brown. Compound eye with sparse short setulae between facets. Thorax ( Figs 16, 18 ). Scutum dark brown with postpronotal lobe and postalar callus yellow; with silvery gray pruinescence; scutellum yellow. Setae: 2 postsutural dorsocentral; 2 notopleural; 1 postpronotal; 1 postsutural intra-alar; 1 post-alar; all setae well developed; scutellum with one preapical and one sub-basal pairs long. Pleura brown, clearer than scutum, with sparse silvery gray pruinescence on some regions; 1 long katepisternal seta and some small setae on ventral half of katepisternum; 1 propleural developed. Wing ( Fig. 19 ) dark gray tinged, pale gray anal margin and one transverse narrow hyaline band at distal third extended from anterior margin to middle of cell M1, yellowish basally and one small yellowish spot on crossvein r-m. Legs short and robust; coxae and femora brown, tibiae brown with medial ring and apices yellow, tarsomeres 1–2 pale yellow and 3–5 pale brown. Fore femur with long robust setae on posteroventral margin; mid coxa with a comb of black strong setae on anterodistal margin; apicoventral spine of mid tibia developed; mid tarsus with ventral black spines on tarsomeres 2–4. Abdomen pale brown; short, ovate, wider on segments 2–3; setae short; tergite 6 slightly longer than the remaining tergites. Terminalia ( Fig. 23 ): syntergosternite 7 narrow; sternite 8 wide and shallowly concave on posterior margin, posterior margin more sclerotized; tergite 8 widened; cercus small.

Male. As in the female except the general coloration of body slightly darker: frons brown with lateral margin yellow; scutum dark brown to black; pleura brown; katepisternal setae 2–3; abdomen dark brown. Terminalia ( Figs 20–22 ): epandrium low, shallowly concave; postgonites long and slender, bar like; ejaculatory apodeme short and wide, basal process of length of ejaculatory apodeme; phallus long, strongly dilated basally and enlarged distally with truncate tip, dense small hairs along dorsal surface; cerci very large with dense long setae, also rounded in posterior view.

Type material. Holotype ♀ ( USNM) labeled: “Porto Bello/ Pan Mar 1911 / August Busck (small white label); “ Type no. 43127 U.S. N.M. (red label); Marbenia peculiaris Det. J. R. Malloch (large white label). Condition of type: good except the ocellar setae lost, medial vertical setae laid flat over compound eyes and frons, left orbital seta lost; scutum and scutellum with a dorsal longitudinal rip; anterior notopleural seta lost.

Other material examined: BOLIVIA, Santa Cruz Dept.: Ichilo Prov., Hotel Flora y Fauna, 4–6 km SSE Buena Vista, 1729.95'S, 6333.15'W, 400–500m, 11 November 2003, N. E. Woodley (1♂; USNM). ECUADOR, Orellana: Res. Etnica Waorani (039.4'S, 7627.2'W; 216m, lot# 953), 8 Feb 1995, T. L. Erwin (1♀; USNM); (039.4'S, 7627.2'W; 216m, lot# 981), 9 Feb 1995, T. L. Erwin (1♂; USNM); (039.4'S, 7627.2'W; 216m, lot# 1693), 1 Oct 1995, T. L. Erwin (1♀; USNM). BRAZIL, Par: Viseu Faz. Ema – Mata, 24.xi–7.xii.1999, 5221ʹ29.6ʺS, 0125ʹ03.5ʺW, Armadilha Suspensa, I.S. Gorayeb, T. Pimentel, R.N. Bittencourt, J.O. Dias (1♂; MPEG).

Distribution. Bolivia, Brazil, Ecuador, Panama.

Remarks. Marbenia peculiaris is easily distinguished from all species of Marbenia by the following characters: face and frons brown, wing predominantly brownish and male cercus large and bearing long setae.

Figures

FIGURES 16 – 19. Marbenia peculiaris Malloch: 16, habitus, lateral view; 17, head, frontal view; 18, dorsum of thorax; 19, left wing, dorsal view.

FIGURES 20 – 23. Marbenia peculiaris Malloch: 20 – 22, male terminalia: 20, posterodorsal view of epandrium and internal terminalia; 21, same, lateral view; 22, ejaculatory apodeme, lateral view. 23, Female terminalia: posteroventral view. Figures 20 and 21 in the same scale. Scale = 0.3 mm.

FIGURES 8 – 11. Marbenia pallida, sp. nov.: 8, habitus, lateral view; 9, head, frontal view; 10, dorsum of thorax; 11, left wing, dorsal view.