Atylobaccha flukiella ( Curran, 1941 )

Miranda, Gil Felipe Gonçalves, Marshall, Stephen A. & Skevington, Jeffrey H., 2014, Revision of the genus Pelecinobaccha Shannon, description of Relictanum gen. nov., and redescription of Atylobaccha flukiella (Curran, 1941) (Diptera: Syrphidae), Zootaxa 3819 (1), pp. 1-154 : 8-9

Atylobaccha flukiella ( Curran, 1941) redescription

Map 1. Figure 1 .

Atylobaccha flukiella ( Curran, 1941)

Baccha flukiella Curran, 1941 . Curran, 1941: 275. Type locality: Brazil, Santa Catarina, Nova Teutônia. Holotype male AMNH. Hull, 1949a: 198 (fig. 39, male abdomen).

Ocyptamus flukiella . Thompson et al., 1976: 18 (catalog citation).

Male. Head: Black. Face narrow, slightly convex with very weak tubercle, white pilose. Lunule entirely black. Frontal triangle mostly shining black with black pile, very weak protuberance medially and lateral white pollen on ventral ½ that merges with the pollinosity from the face. Vertical triangle with only 1 median row of pile; ocellar triangle separated by its length from posterior eye margin. Eye contiguity 2.5 times as long as vertical triangle length. Eye with posterior indentation triangular and at level of antennal insertion. Antennal insertions confluent; antennal bases very close to each other, antenna dark brown, basoflagellomere pale baso-ventrally, oval short. Dorsal ¼ of occiput with sparse white pollen, ventral ¾ covered with dense white pollen, dorsal ¼ with 1 row of simple black pile, middle ¾ with 2 rows of scale-like white pile, anterior row shorter.

Thorax: Scutum black, sometimes shiny, with sparse white pollen and inconspicuous sub-median anteroposterior pair of pollinose vittae, black or white pilose, pile slightly longer on notopleuron, anterior row with slightly longer pile interrupted in the middle by shorter pile. Scutellum black, white pilose, with sparse white pollen, subscutellar fringe pile white. Pleuron black, sometimes slightly lightened on posterior ½ of posterior anepisternum; white pilose on anepisternum, dorso- and ventro-posterior katepisternum, anterior anepimeron and meron, metepisternum bare, katatergite with short microtrichia that gives it a velvet-like appearance. Plumula very short and white. Calypter white, dorsal lobe fringe with distinct pile, but still shorter than pile from ventral lobe fringe. Halter white to light yellow.

Wing: Hyaline to light brown, entirely microtrichose; alula twice as wide as distal width of cell c, entirely microtrichose.

Legs: Legs mostly pale and white pilose, coxae black. Profemur and protibia usually with light brown subapical band, protarsus brown. Mesofemur usually with light brown subapical band. Metafemur with subapical dark brown band, metatibia with medial dark brown band, metabasitarsomere mostly dark brown but apex pale, remaining metatarsomeres pale.

Abdomen: Dark brown; about 3 times as long as thorax. First tergite crescent-shaped from a dorsal view, short and curving gently posteriorly on both sides, usually with wide lateral surface and very long, mostly pale, pile. Second segment long and narrow, length 6 times minimum width, with medial pair of fasciate pale maculae and subapical arcuate fascia of dull black pollen extended posteriorly as medial vita; pile appressed and black dorsally, otherwise long, erect and white. Third tergite trapezoidal, 2.5 times as long as minimum width, with mainly appressed black pile; with central pair of short pale vittae and sub-basal pair of lateral fasciate pale maculae (sometimes connected basally to vittae) and central triangular macula of dull black pollen, pollen absent on the pale maculae; 3rd sternite rectangular, long and narrow. Fourth tergite sub-quadrate, usually slightly longer, fasciate maculae sometimes triangular; remaining characters as on 3rd. Fifth tergite rectangular and wide, with 4 short pale vittae; dull pollinose region divided into 3 median vittae; remaining characteristics as on 4th. Genitalia: Epandrium wide but short, cercus with 3 regular rows of pile. Surstylus sub-triangular and short, directed ventrally, with very sparse ventral setulae. Subepandrial sclerite homogenously sclerotized, rectangular, wide and short, with short acute baso-lateral corners. Hypandrium oval with basal ½ expanded ventrally, ventral notch trapezoidal and on apical ½. Phallapodeme well sclerotized and tapering towards base. Basiphallus teardrop-shaped in dorsal view, with posterior extremity rounded; distiphallus smaller than basiphallus with only an anterior triangular sclerotization. Postgonite sparsely pilose baso-ventrally, with rounded apex and dorsal acute extremity, ventral surface slightly concave, dorsal surface straight.

Female: Like male except: Frons white pilose, narrow but widening from vertex. Vertex narrow, lateral white pollen reaching ocellar triangle; ocellar triangle 1.5–2 times its length from posterior eye margin and adjacent to lateral eye margin. Alula narrower. Second abdominal segment with shorter lateral pile. Third tergite shorter. Fourth tergite rectangular and wide. Sixth segment short, a ⅓ of the length of the 5th. Genitalia: Seventh tergite rectangular and wider, with pile only on apical ½; 7th sternite mostly membranous. Eighth tergite rectangular and wide with shallow notch on anterior and posterior margin; 8th sternite reduced to pair of triangular sclerites. Tenth tergite reduced to a pair of quadrate sclerites, with narrow baso-lateral projection on each sclerite; 10th sternite not discernible. Cercus separate from 10th tergite, densely pilose and well sclerotized.

Length. 5.5–7mm; wing 4–5mm.

Distribution. Brazil (Rio de Janeiro, Santa Catarina), Peru (Junín).

Material examined. BRAZIL. Santa Catarina, Nova Teutônia, 300–500m, 27°11'S 52°23'W, Jun 1964, F. Plaumann (2 ♂, CNC Diptera 190104 –5, 1 ♀, CNC Diptera 190101); ..., Ponte Serrado, 26°54'S 51°58'W, 0 2 Mar 1962, F. Plaumann (1 ♀, CNC Diptera 190103); Rio de Janeiro, Itatiaia, Macieiras, 1800m., Jan 1948, C.D. Andretta (1 ♂, CNC Diptera 190102). PERU. Junín, Chanchamayo, San Ramón, Sector Quebrada Santa Rosa, “Fundo Génova”, Malaise trap, 11°05'44.4”S 75°21'19.6''W, 1080m., CAVXM 033, 07–10 Jul 2008, X. Mengual (1 ♂, ZFMK).

Figures

FIGURE 1. Atylobaccha flukiella (Curran, 1941). a. Head, lateral. b. Wing. c. Female genitalia, dorsal. d – f. Male genitalia: d. Hypandrium, lateral. e. Epandrium, dorsal. f. Epandrium ventral. g. Holotype, habitus, dorsal (copyright AMNH). 8 tg: 8 th tergite, 10 tg: 10 th tergite, cerc: cercus, s scl: subepandrial sclerite, surst: surstylus.