Pelecinobaccha levissima ( Austen, 1893 ) Austen, 1893

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 : 51

Pelecinobaccha levissima ( Austen, 1893) comb. nov.

Map 5. Figure 7 .

Baccha levissima Austen, 1893 .— Austen, 1893: 146, pl. 4: fig 15 (habitus). Type locality: Brazil, region of Amazon. Holotype male BMNH (not examined). Hull, 1949a: 238 (fig. 220, male abdomen), 268 (fig. 337, male wing).

Ocyptamus levissimus . Thompson et al., 1976: 21 (catalog citation).

Baccha bassleri Curran, 1939 .— Curran, 1939: 8. Type locality: Peru, Middle Rio Ucayali. Holotype male AMNH. Hull, 1949a: 238 (fig. 219, male abdomen), 256 (fig. 297, male wing). n. syn.

Ocyptamus bassleri . Thompson et al., 1976: 13 (catalog citation).

As in P. brevipennis except: Male. Ocellar triangle separated by less than its length from posterior eye margin. Eye contiguity longer than vertical triangle length. Occiput middle 2⁄4 anterior rows always with simple black pile. Scutum mostly covered by brown pollen and with median vitta of absence of pollen; scutum anterior row with incospicuous shining white pile. Plumula virtually absent, some specimens with a few short pile on dorso-posterior margin of dorso-medial anepimeron. Calypter dorsal lobe with marginal fringe of short sparse pile. Wing entirely light brown; alula basal width as narrow as c cell, but expanding abruptly on apex to 3 times its basal width, light brown. Legs dark brown. Mesofemur posterior row with dark pile. If maculae present on abdominal tergites, then maculae very faint. Genitalia: Surstylus slightly longer, directed ventrally, with more setulae apically. Subepandrial sclerite quadrate with more pronounced concave posterior margin. Hypandrium sub-oval with narrower quadrate apical ⅓. Phallapodeme longer, ⅔ the length of the hypandrium. Distiphallus with anterior surface slightly sinuous. Postgonite with dorsal surface straight, apex gently convex, with acute dorsal extremity and slightly rounded ventral extremity.

Female: Like male except: Frons normal width, rugose on ventral ¼, black, dull brown-pollinose medially, dull black-pollinose in a diamond-shaped region dorsal to frontal prominence, white-pollinose lateral maculae larger and not continuous to lateral pollen from face. Ocellar triangle ~1.5 times its length from posterior eye margin and ~1 ocellus-width from lateral eye margin. Scutum dull brown-pollinose, with white pollen laterally and forming a pair of sub-median vittae; pile posterior to transverse suture dark, without anterior row of shining white pile. Wing lighter. Legs pale. Mesofemur with subapical ring of light brown; posterior row of mesofemur with shorter pile. Apical 2/5 of metafemur, metatibia and all tarsi dark brown. Abdomen ~5.5 times as long as thorax; whole abdomen with very short black pile. Second tergite very long, length 5 times minimum width, and with subapical fascia and sub-basal spots of dull black pollen, fascia sometimes interrupted medially. Third tergite long, length ~3.5 times minimum width; dull black maculae as on 2nd tergite. Fourth tergite long, ~2.5 times as long as wide. Fifth segment sclerites fused laterally on apical ½. Sixth segment whole, very short, a ⅓ of the length of the 5th segment. Genitalia: 7th tergite short triangular. Subapical stripe of 8th tergite not extended baso-medially, basal crest short. Cercus with apical margin slightly undulate and with ~4 irregular rows of pile on ventral ½.

Length. 11–13mm; wing 6.5–7.5mm.

Distribution. Brazil (“region of Amazon”), Peru (Madre de Dios, Ucayali).

Material examined. PERU. Madre de Dios, Avispas , 400m., 10–20 Sep 1962, L. Pena (1 ♀, CNC Diptera 161337); ..., Chiforongo, 11 Oct 1963, L.E. Pena (1 ♀, CNC Diptera 161336); ..., Manu, Rio Manu, Pakitza, 250m, 12°7'S 70°58'W, 9–23 Sep 1988, A. Freidberg (1 ♂, USNM); [Ucayali], Pucallpa , 18 Nov & 0 3 Dec 1947, J. Shunke (2 ♂, CNC Diptera 161334–5); ..., Frank M. Hull Collection C.N.C. 1973, 0 5 Feb 1948, J. Shunke (1 ♀, CNC Diptera 161338).

Comments. Austen distinguished Baccha levissima from B. brevipennis by “the yellow spots on the abdomen and by the infuscated wings”. The yellow spots don’t seem to be a reliable character since they do occur on specimens of P. brevipennis , and specimens of P. levissima usually have only faint maculae. Still, the wings of the two species are distinctly different and the additional characters given here add support to their separation. The type specimen of B. bassleri is missing the abdominal segments beyond the 2nd, but the remaining characters agree with the redescription of P. levissima .

Figures

FIGURE 7. Pelecinobaccha levissima (Austen, 1893). a – c. Female genitalia: a. Dorsal. b. 7 th segment, lateral. c. Apex, lateral. d – f. Male genitalia: d. Epandrium, ventral. e. Hypandrium, lateral. f. Hypandrium, ventral. g. Male, habitus, dorsal. 7 tg: 7 th tergite, 8 tg: 8 th tergite, 10 tg: 10 th tergite, cerc: cercus, s scl: subepandrial sclerite.