Pelecinobaccha pilipes ( Schiner, 1868 ) Schiner, 1868

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 : 65-67

Pelecinobaccha pilipes ( Schiner, 1868) comb. nov.

Map 9. Figure 37 .

Baccha pilipes Schiner, 1868 .— Schiner, 1868: 342. Type locality: “South America ”. Lectotype male NHMW. Hull, 1949a: 210 (fig. 94, male abdomen), 272 (fig. 350, male wing).

Ocyptamus pilipes . Thompson et al., 1976: 25 (catalog citation).

Baccha hirta Shannon, 1927 .— Shannon, 1927: 11. Type locality: Bolívia, Beni, Ivon. Holotype male USNM. Hull, 1949a: 154 (redescription), 250 (fig. 271,

male abdomen). n. syn.

Ocyptamus hirtus . Thompson et al., 1976: 20 (catalog citation).

Baccha nigrocilia Hull, 1943 .— Hull, 1943e: 215. Type locality: Brazil, São Paulo, Ilha Seca. Holotype female AMNH. Hull, 1949a: 162 (redescription), 245 (fig. 248, female abdomen). n. syn.

Ocyptamus nigrocilia . Thompson et al., 1976: 23 (catalog citation)..

Baccha nigrocilia var. hirtipes Hull, 1943 .— Hull, 1943e: 215. Type locality: “ Colombia ”. Allotype female AMNH. Hull, 1949a: 221 (fig. 139, female abdomen). n. syn.

Ocyptamus nigrocilia var. hirtipes . Thompson et al., 1976: 23 (catalog citation).

Baccha nigrocilia var. inclusa Hull, 1943 .— Hull, 1943e: 215. Type locality: “ Colombia ”. Allotype female AMNH. Hull, 1949a: 225 (fig. 156, female abdomen). n. syn.

Ocyptamus nigrocilia var. inclusa . Thompson et al., 1976: 23 (catalog citation).

Male. Head: Shiny black. Face pale on lateral ¼, sometimes only slightly lightened; gena dark brown. Lunule black, with small pale area above antenna insertion. Frontal triangle entirely black, white pollen restricted to lateromedial oval spots and a small patch of differently oriented pollen ventrally, not connected to face pollen. Vertical triangle with 3 rows of pile, but most pile concentrated in a single row ending dorsal to anterior ocellus; ocellar triangle separated by its length from posterior eye margin. Eye contiguity as long as the vertical triangle length. Eye with sub-triangular indentation on posterior margin positioned around level of antenna insertion. Antennal insertions almost separated, ventral sclerotized margin extended dorsally, scape with longer pile. Occiput usually with dull dark pollen on dorsal ⅓ and with white pollen on ventral ⅔; dorsal ⅓ of occiput with 2 rows of simple black pile, anterior row slightly shorter; middle ½ with anterior 2–3 rows of simple black pile, posterior row longer, scale-like and white; ventral ¼ with 2–3 irregular rows of scale-like white pile.

Thorax: Scutum black with dull dark pollen, except white on notopleuron, with no distinct rectangular concentrated area anterior to scutellum; scutum with long black pile, densely arranged, slightly shorter laterally posterior to transverse suture, and with anterior row slightly longer and sometimes white. Scutellum dark brown, pile black and long, subscutellar fringe copious (around 60 pile), pile long and black, sometimes white. Pleuron dark brown to black and with long black pile on anterior anepisternum, posterior ½ of posterior anepisternum, anterior anepimeron, ventro- and dorso-posterior katepisternum, katepimeron and metaepisternum, these regions sometimes with white pile intermixed, and the pile is densely arranged on the posterior anepisternum, anterior anepimeron and dorso-posterior katepisternum. Plumula long and dark brown. Calypter and fringe black. Halter dark brown, capitulum yellow to orange.

Wing: Mostly hyaline, dark on the stem cell, cell bc and base of bm, sometimes dark on cells c, sc, and basal regions of r1 and r2+3, either entirely microtrichose or with central bare areas (see comments below); alula with anterior margin dark, large; basally as broad as and apically 4 times as broad as cell c, entirely microtrichose.

Legs: Proleg dark brown. Mesoleg dark brown. Metaleg dark brown, pale on apex of metabasitarsomere, 2nd and 3rd metatarsomeres; metafemur and metatibia with densely arranged long pile.

Abdomen: Black, 2.7 times as long as thorax. First tergite mainly black pilose, pile white ventrally. Second tergite long, length ~2.5 times minimum width, with curved fasciate region of dull black pollen medially that slightly expands basally; 2nd tergite with mainly densely arranged long white pile, except for appressed black pile on apico-dorsal ½. Third tergite trapezoidal, sometimes pale on baso-lateral ½, with large triangular region of dull black pollen medially; 3rd tergite with mainly appressed and black pile, except with some white, longer and erect pile on baso-lateral corners; 3rd sternite dull black-pollinose on a medial spot. Fourth tergite rectangular and wide, with pair of inconspicuous short central pale vittae and large baso-lateral pale triangles, might appear entirely black; 4th tergite with large triangular region of dull black pollen medially, and mainly with appressed and black pile, except white on baso-lateral corners. Fifth tergite rectangular and narrow, wider than long, and dull blackpollinose medially but with pair of subshining medial vittae, and with appressed black pile. Genitalia: Cercus with 1 regular row of pile on medial margin and 3 irregular rows on lateral margin. Surstylus directed apically, with rounded apex, with strong setulae (around 10) concentrated on ventral apical ⅓, with very little of the dorsal thin sclerotized layer, pilose on basal ½ of the dorsal surface. Subepandrial sclerite quadrate, antero-lateral corners slightly extended, postero-lateral corners extended posteriorly and laterally. Hypandrium almost entirely open on ventral side. Phallapodeme with basal ⅓ poorly sclerotized. Distiphallus smooth and anterior surface straight. Postgonite with pile mainly on ventral surface, ventral surface expanded, slightly convex until dorso-apical extremity, dorsal surface slightly concave; postgonite apex convex anteriorly, with acute dorsal extremity.

Female: As male except: Face usually distinctly pale laterally. Frons broad. Vertex with short pile concentrated on single row ending dorsal to anterior ocellus; ocellar triangle ~2 times its length from posterior eye margin and 1.5–2 ocelli-width from lateral eye margin. Wing with basal ⅓ dark (dark on cell c, basal ½ of sc, basal ¼ of r1, base of r2+3, ¾ of r and bm, cu p diffusely dark); alula entirely dark. First 3 tarsomeres of the protarsus and mesotarsus greatly enlarged, 4th tarsomere normal, 5th tarsomere reduced. Abdominal pile from 2nd tergite onward usually much shorter than on male. Third and 4th tergite usually with pale triangular maculae on baso-lateral corners. Sixth segment short, segment base wider than long, as long as 5th. Genitalia: 7th tergite with undulated apex, basal extensions as long as the 6th segment; 7th segment lateral sclerite narrow and long; 7th segment with central dorsal longitudinal membranous area bare. Eighth tergite central region well sclerotized, basal crest weakly sclerotized. Cercus with 1–2 rows of pile on apical margin, with short basal extension.

Length. 9–11mm; wing 7–8.5mm.

Distribution. Bolivia (Beni), Brazil (Goiás, Mato Grosso), Colombia (Boyaca), Ecuador (Napo), Paraguay (Paraguari), Peru (Cuzco, Madre de Dios, Pasco), Venezuela.

Material examined. BOLIVIA. Beni, Ivon, Mulford Biol Expl, Type no 28759 U.S. N.M. [red label], USNM 2052087, Feb 1921–22, W. M. Mann (1 ♂, holotype Baccha hirta , USNM). BRAZIL. Goiás, Corumbá, F. Monjolinho, Nov 1945, [M.P.] Barretto (1 ♂, MZSP); [Mato Grosso], Chapada, S. W. Williston Collection, Am.

Mus. Nat. Hist. Dept. Invert. Zool. n°19195, Jan (1 ♂ & 1 ♀, AMNH); ..., Utiariti, Rio Papagaio Mt, Oct 1966, [K.] Lenko & Pereira (1 ♂, MZUSP). COLOMBIA. Boyaca, Muzo, 900m, Frank M. Hull Collection C.N.C. 1973, 1936, J. Bequaert (1 ♀, CNC Diptera 160832); Meta, Restrepo, 500m, Frank M. Hull Collection C.N.C. 1973, 1936, J. Bequaert (1 ♀, CNC Diptera 160833). ECUADOR. Limoncocha, 0°24' S, 76°40' W, 250m., 9–16 Mar 1976, G. E. Shewell (1 ♀, CNC Diptera 160834); Napo, Coca, Napo R., 250m, 25–30 Apr & May 1965, L. Pena (1 ♂, CNC Diptera 160841, 4 ♀, CNC Diptera 160835 –8). MEXICO. Tehauntepec. Sumichrast, C. V. Riley collection (1 ♂, USNM ENT 00257703). PARAGUAY. Paraguari, Ybycui (25 km SE), in Ybycui National Park, 12–24 Apr 1980, P. J. Spangler et al. (1 ♂, USNM ENT 00257704). PERU. Cuzco, Quincemil, 780m, 13–31 Aug 1962, L. Pena (2 ♀, CNC Diptera 160839 –40); Loreto, Iquitos (14 km W), 21 Feb 1984, W. N. Mathis (1 ♀, USNM ENT 00257696); Madre de Dios, Avispas , 400m., 20–30 Sep 1962, L. Pena (1 ♂, CNC Diptera 160842); ..., Manu, Rio Manu, 250m., Pakitza, 12°7'S 70°58'W, 9–23 Sep 1988, Amnon Freidberg (1 ♀, USNM ENT 00257701); Pasco, Yonculmaz, R. Cacazú, 700m, 5 Apr 1984, P. Hocking (1 ♀, USNM ENT 00257705). VENEZUELA. Lindig, Baccha pilipes Schin. [handwritten label], [label with unintelligible handwriting], Lectotype Baccha pilipes Schiner [red label], 1864 (1 ♂, lectotype Baccha pilipes , NHMW); …, Paralectotype Baccha pilipes Schiner [red label]1864 (1 ♀, paralectotype Baccha pilipes , NHMW).

Comments. Schiner’s description of Baccha pilipes did not indicate where the types were deposited, but included comments about “ein pärchen” (a pair) of specimens from South America. The male specimen from the type series of the NHMW is hereby set as the lectotype in order to stabilize the concept of this species.

Baccha hirta Shannon, 1927 was described as “An easily recognized species because of its unusually long, stiff, erect, and black vestiture, a unique character in this genus.” We gather that Shannon must have not seen B. pilipes type specimens, or else he wouldn’t have described the pile characters as unique.

Baccha nigrocilia Hull, 1943e and its variations (hirtipes and inclusa) were separated from B. pilipes in Hull’s (1949a) key by the extent of black on the wing (only base for B. pilipes and basal ½ dark, although might be dilute, for the others). This is a sexually dimorphic character, and the difference that Hull (1949a) uses in his key separates males from females of this species. Schiner had previously alluded to this fact (“Flügel glashell, an der Basis schwarz, was sich bei dem Weibchen etwas mehr ausbreitet als bei dem Männchen”—Wing transparent, black at the base, which is somewhat more widespread in the female than on the male). Hull (1949a) stated that B. nigrocilia is related to B. hirta but, although both were redescribed in that same paper, B. hirta never appeared in the key and we are unsure why Hull would erect B. nigrocilia if he studied B. hirta .

One female from Venezuela and four males, from Bolivia, Ecuador, Peru and Venezuela, have distinct bare regions on their wing cells. The female is bare on the anterior margin of the c cell, apical ⅓ of r, middle 3/5 of r1, basal 6/7 of r2+3 (except on middle fold), basal ¾ of r4+5 and baso-anterior margin of cu p. The male from Ecuador is bare only in the middle anterior margin of r and the baso-anterior margin of the cu p cell. The male from Peru and the lectotype are bare on basal 2/5 of c, most of the apical 4/5 of r (microtrichose around sv vein), some regions on the middle anterior margin of r2+3, basal region and posterior to the sv vein on r4+5, median 3/5 of bm and basal ⅓ of cu p cell. The holotype of B. hirta is bare on the middle ⅓ and posterior apex of r (except around the sv vein), base of r1, some regions on the anterior margin of r2+3, middle ⅓ of the anterior margin of bm and anterior margin of cu p.

Bare areas on the wing are rare in the Pelecinobaccha group, but since no other characters support the separation of these specimens into different species, the bare areas are treated as an intraspecific variation, and B. hirta is here treated as a junior synonym of B. pilipes .

Figures

FIGURE 37. Pelecinobaccha pilipes (Schiner, 1868). a – d. Female: a. Metaleg, lateral. b – d. Genitalia: b. 7 th tergite, dorsal. c. Apex, dorsal. d. Lateral. e – j. Male: e. Head and thorax, dorsal. f. Head and thorax, lateral. g – j. Genitalia: g. Epandrium, lateral. h. Epandrium, ventral. i. Hypandrium, lateral. j. Hypandrium, ventral. 8 tg: 8 th tergite, 10 tg: 10 th tergite, cerc: cercus, s scl: subepandrial sclerite.