Pelecinobaccha impostor

Miranda, Gil Felipe Gonçalves, 2017, Revision of the Hybobathus arx and Pelecinobaccha summa species groups (Diptera: Syrphidae), Zootaxa 4338 (1), pp. 1-43: 32-35

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Pelecinobaccha impostor

sp. nov.

Pelecinobaccha impostor  sp. nov.

Fig. 10View FIGURE 10

Description. MALE ( Figs 10a, c, e & h –lView FIGURE 10). Head ( Fig. 10hView FIGURE 10). Black. Face mainly yellow except for a dark brown marking on the tubercle, mainly black pilose with some white pile ventrally; microtrichia concentrated on lateral 1/ 5. Gena white pilose. Lunule slightly pale dorsal to antennal insertion, with central black marking broadly connected to frontal triangle color. Frontal triangle black but yellow laterally almost until eye contiguity and continuous from face, silver microtrichose medially and dull dark microtrichose between the silver microtrichia and the yellow lateral sides, with sparse white microtrichia laterally, visible from a ventro-lateral angle. Frontal prominence slightly protuberant. Vertical triangle black, with a single median row of erect black pile ending dorsally to anterior ocellus; ocellar triangle separated by its length from the posterior eye margin. Eye contiguity as long as vertical triangle length. Eye with weak sub-triangular indentation on posterior margin positioned slightly dorsal to level of antennal insertion. Antennal insertions confluent, ventral margin with short dorsal acute extension. Antennae brown and with black pile; postpedicel oval and yellow baso-ventrally. Occiput homogenously covered by white microtrichia, dorsal 1/3 with 1–2 rows of long simple black pile, ventral 2/3 with 2–3 regular rows of flattened white pile, anterior row shorter and with some dark pile dorsally. Thorax ( Fig. 10aView FIGURE 10). Postpronotum yellow; scutum black, but with sub-lateral yellow vitta extending from postpronotum to postalar callus, mostly sparse dull microtrichose except for three median narrow vittae of concentrated microtrichia, median vitta slightly expands and tapers again posteriorly and sub-median pair slightly shorter and tapering posteriorly; with erect black pile, except white on notopleuron (but with some black pile intermixed anterior to transverse suture) and medially on posterior 1/2; with anterior continuous row of white pile. Scutellum yellow, with erect, long black pile; subscutellar fringe with long and black pile. Pleuron dark brown, yellow on posterior 1/2 of posterior anepisternum, tegula and dorso-posteriorly on the katepisternum, with pale pile on anterior anepisternum, posterior 1/2 of posterior anepisternum, on separate dorsal and ventral patches on katepisternum, anterior anepimeron, katepimeron, and metaepisternum, with one to three black pile on dorso-posterior margin of posterior anepisternum; basal wing sclerites with a single projection on each. Plumula long and white. Calypter yellow, margin of dorsal lobe with short white pile, ventral lobe narrow and margin with long white pile. Halter white. Wing ( Fig. 10cView FIGURE 10). Dark brown, entirely microtrichose; alula linear, at most apically twice as broad as c cell, entirely microtrichose. Legs ( Fig. 10cView FIGURE 10). Prolegs yellow, procoxae brown, apical 1/2 of profemora light brown, pile black, longer on baso-posterior 1/2 of profemur. Mesolegs yellow, brown on mesocoxae and mesotrochanters, pile as on prolegs but with rows of longer pile on the whole posterior surface of the mesofemur. Metalegs dark brown, pale on apex of metafemora and basal 1/5 of metatibia, yellow on apical 2/5 of metabasitarsomere and remaining metatarsomeres, mostly black pilose except metacoxa with black and white pile, and tarsomere 2 and onward with pale pile. Abdomen ( Figs 10a & eView FIGURE 10). Petiolate and narrow, 3.8 times longer than thorax, dark brown. Tergite 1 light yellow laterally, with long, erect black pile; sternite 1 pale and with erect white pile. Tergite 2 long, 5 times longer than smallest width, with pair of oblique fasciate yellow markings medially, with central rectangular region of dull dark microtrichia, and with long, erect, black pile, shorter and appressed dorsally; sternite 2 dark brown except for pale apex, and with very sparse and appressed black pile. Tergite 3 trapezoidal long, 3 times longer than apical margin, with lateral margin meeting the sides of sternite 3, giving the segment a more cylindrical appearance, with pair of lateral yellow vittae on basal 1/3 and a long pair of central yellow vittae on basal 3/4, the latter slightly expanding apically, with large central triangular region of dull dark microtrichia, with short, appressed, black pile; sternite 3 narrow and long. Tergite 4 rectangular, long, 1.8 times longer than wide, with basal lateral margins curving and meeting the sternite, giving this tergite a more trapezoidal appearance, remaining characters as on tergite 3, except median pair of vittae almost reaches apical margin and the dull microtrichia forms a rectangular region; sternite 4 trapezoidal. Tergite 5 sub-quadrangular, remaining characteristics as on tergite 4, except medial vittae narrowly touching the apical margin. Genitalia ( Figs 10i –lView FIGURE 10). Cercus with a row of pile on medial margin and two rows sub-laterally. Surstylus sub-oval in dorsal view, with a few sparse pile on basal 1/3 and medial margin of dorsal surface. Subepandrial sclerite quadrate with baso-lateral margins extended posteriorly for 1/3 of the length of the sclerite. Hypandrium oval on basal 1/2 and slightly narrower and rectangular on apical 1/2, ventral notch extending on anterior 2/3 and with triangular posterior margin. Phallapodeme weakly sclerotized, tapering posteriorly. Basiphallus drop-shaped, gently tapering towards base. Distiphallus anterior surface almost straight and tapering at apex and with baso-lateral extensions that meet ventrally (forming a tube). Postgonite expanded baso-posteriorly, dorsal surface slightly concave, ventral surface straight, apex convex, with convex ventral extremity and acute dorsal extremity.

FEMALE ( Figs 10b, d, f, g & m –qView FIGURE 10). Like male except for the following characters: Brown marking on facial tubercle lighter. Frons black, yellow laterally almost until ocellar triangle; with dull pale microtrichia, absent laterally except for small lateral areas anterior to the ocellar triangle that are oriented dorso-ventrally. Vertex with shorter pile; ocellar triangle twice its length in front of posterior eye margin. Postpedicel mostly dark. Subscutellar fringe white. Calypter white. Halter white, capitulum orange. Wing brown but with large sub-apical pale spot (pale on small sub-apical area on r1, middle 1/3 of r2+3, sub-basal 1/2 of r4+5 and anterior sub-apical area of dm). Procoxa black, pile yellow on procoxa, dorsally on protibia, and on protarsus. Metaleg mostly yellow, metafemur dark sub-apically, metatibia dark on apical 3/4, metabasitarsomere dark on basal 1/4, pile mostly black, pale on metacoxa and pale areas of the metatarsus. Abdomen 3 times longer than thorax. Abdominal tergite 1 with basal 1/ 2 pale, pile pale baso-ventrally. Tergite 2 shorter, 3.4 times longer than minimum width, fasciate markings with anterior and posterior concavities, all pile appressed. Tergite 3 trapezoidal long, 1.5 times longer than apical margin and apical margin around 2 times wider than basal margin. Tergite 3 with baso-lateral pale triangular markings that join with central vittae basally, central vittae longer; sternite 3 trapezoidal and long. Tergite 4 quadrate, central vittae reach the apical margin. Tergite 5 rectangular, wider than long, lateral margins yellow and central vittae uniform and reaching apical margin. Segment 6 shorter than its basal margin and shorter than 5. Genitalia ( Figs 10n –qView FIGURE 10). Tergite 7 sub-rectangular, with convex apical margin, with pile mostly on membranous apical area, only a few on the apex of the sclerite, and with long baso-lateral apodeme; segment 7 lateral sclerite triangular, tapering towards truncated apex, with very short baso-ventral apodeme; ventral area of segment 7 wholly membranous, pile restricted to apical and lateral areas. Membranous area between segments 7 and 8 as long as tergite 8. Tergite 8 triangular, with triangular indentation on basal margin and two dorsal ridges on basal crest, sclerotization restricted to lateral and basal margins of the tergite, basal crest much reduced, bare; sternite 8 as two lateral plates, with sclerotization restricted to margins, with curved acute projection on ventro-apical corner and acute projection on ventro-basal corner, membranous medially, pile restricted to medial membranous area. Epiproct fused to cerci, basal apodeme rounded, granting the epiproct a bilobated base, bare; hypoproct as a sclerotized strip, pilose. Cerci sclerotized, flat, pile restricted to apical margin, on the same plane as the epiproct (due to fusion) and on a perpendicular plane to that of tergite 8. Spermathecae ovoid with small protuberances on one side of their surface.

Length. Body: male 10.2–12.5mm (n = 2), female 11mm; wing: male 7.6–9.7mm, female 9mm.

Variation. MALE. Dorsal 1/3 of the occiput with a single row of pile. Abdominal sternite 1 with mostly black pile; tergites 3 and 4 lateral margins might not curve as much.

Distribution. Colombia (Valle del Cauca), Venezuela (Lara).

Etymology. The specific epithet impostor  means the same in English, and refers to the fact that this species ‘tricks’ one to believe it is part of the Ocyptamus lepidus  group rather than Pelecinobaccha  . It should be treated as a noun in apposition.

Comments. The overall appearance of this species is similar to species from the O. lepidus  species group [e.g. O. octomaculatus Thompson in Thompson et al., 1976  and O. zita ( Curran, 1941)  ], specially since the segment 6 is shorter and not typically cone-like as in other Pelecinobaccha  from the summa  species group. Nevertheless, it has more than one row of pile on the dorsal occiput (at least on the holotype), the face is dark medially (wholly pale in the O. lepidus  group), the male genitalia lack the bilobed projection between the surstyli (typical of the O. lepidus  group), the female frons is much darker and its ocellar triangle is not so anteriorly displaced, and the female genitalia is undoubtedly from the genus Pelecinobaccha  . Some other species of the O. lepidus  group diverge also on the markings of abdominal segments 2 (with four medial markings) and 3 (with medial sub-lateral markings not reaching the base). The central, long, oval vittae of the abdomen are somewhat similar to those of P. cubensis  , suggesting a possible closer relationship, although the darker frons/frontal triangle are closer to P. summa  . This species seems restricted to high altitutdes based on the few localities where this species was found (Andean regions of Colombia and Venezuela).

Type material. HOLOTYPE: Male specimen in good conditions; “Yacambu National Park, Blanquito Lagoon, Lara, Venezuela, 1471m, 9°42'10''N 69°34'21''W, 0 7 Sep. 2008, J. Skevington” “CNC_ Diptera  203527” “Holotype Pelecinobaccha impostor  Miranda” [red label]. PARATYPES: COLOMBIA. Valle del Cauca, 6 mi. W Cali, 20.iii.1955, leg. R.I. Schlinger & M.S. Ross (USNMENT01288150) [1 ♀, USNM]. VENEZUELA. Lara, Yacambu National Park, along main road, 4.ix.2008, leg. M.D. Jackson (JSS25795) [1 ♂, CNC]; Yacambu National Park, sector El Blanquito, 14–21.ix.2001, leg. R. Briceño et al. (ZFMK-DIP-00018039) [1 ♀, ZFMK].