Mberu pepocatu Capellari & Amorim

Capellari, Renato Soares & Amorim, Dalton De Souza, 2011, Mberu, a new neurigonine genus from southeastern Brazil (Diptera: Dolichopodidae), Zootaxa 3101, pp. 38-46 : 40-44

Mberu pepocatu Capellari & Amorim sp. nov.

( Figs. 1–11 )

Diagnosis. As for the genus.

Material examined. HOLOTYPE ♂, BRAZIL, Minas Gerais, Cabo Verde, 21º27'11''S 46º20'52''W, 598 m, Malaise trap, 10–23.ix.2006, Amorim, Ribeiro, Falaschi & Oliveira leg. (mounted on slide). PARATYPES: 1 ♂, 4 ♀ (1 mounted on slide), same data as holotype, but 11.viii.–13.x.2007, Amorim, Oliveira & Capellari leg.

Description. Male ( Fig. 1 ): Body length: 3.3–3.7 mm. Wing: 3.0– 3.1 mm long, 1.1–1.2 mm wide. Body mostly dark brown with shining black reflections, covering bristles varying from black and pale brown to pale white. Head: Frons width 2/3 head width; at narrowest part, face as narrow as middle ocellus, slightly wider at ventral and dorsal ends; vertex slightly excavated dorsally; palpus brown, covered by small black setae, one stronger at apex; proboscis brownish, with many brownish setae; 1 pair of strong, black divergent ocellar setae, and pair of black, slightly convergent, proclinate vertical setae; 1 pair of medium size, brownish paravertical setae; occiput distinctly concave above, shining dark green, and complete row of pale postocular setae, increasing in size towards apex; lower surface of occiput covered by many pale, elongated, and somewhat sinuous setae. Scape short, yellow, dorsal surface bare; pedicel rounded, short, dark yellow, crown of setulae at apex; first flagellomere triangular, as long as scape plus pedicel, brown, pubescent; stylus subapical to dorsal, bare, displaced laterally, bi-articulated at base. Thorax: Brown, with some dark green reflections, elongate, almost as long as abdomen, posterior slope of mesonotum distinctly flattened, postpronotal lobe with lower pale spot. Short scattered setae from anterior end of mesonotum to slightly beyond transverse suture; two rows of 13–15 small acrostichal setae, reaching mesonotal slope; 6 pairs of dorsocentrals, increasing in size posteriorly, last three conspicuously larger; 1 post-sutural intraalar seta, 1 small pre- and 2 large post-sutural supra-alar setae; 2 postpronotals, 1 strong and 1 minute, pale seta; anaproepisternum with 1 pale seta, kataproepisternum with 2 pale setae; 2 notopleurals, 1 large postalar seta, and 1 setula anteriad; 1 pair of strong medial scutellars and 1 pair of smaller laterad setae, about half as long as medial scutellars. Wing ( Fig. 10 ): Membrane very light brown, slightly darker along anterior margin, veins brown, venation greatly modified, reticulated, with short spurious veins arising perpendicularly from R4+5, M, dm-cu, and CuA, those at apex of R4+5 and M slightly anastomosed, membrane around apex of most spurious veins brownish (MSSC). C ending before wing apex, only very shortly extended beyond R4+5; Sc ending at middle of R1; R1 ending at about basal third of wing; R2+3 and R4+5 strongly displaced towards anterior margin, anterior cells strongly compressed, R2+3 ending in C at apical fourth of wing; CuA1 incomplete, ending very close to wing margin; A1 evanescent, not reaching wing margin. Cilia of squamula pale, long. Legs: I: 2.7, 2.2, 1.5, 0.3, 0.2, 0.1, 0.2; II: 3.2, 2.5, 2.2, 0.7, 0.4, 0.2, 0.2; III: 3.9, 3.6, 1.5, 1.6, 0.9, 0.5, 0.3. Mostly dark brown, yellow at ventral surface of tibia II, IIt1 except apex, median ring on tibia III, and basal excavation on IIIt1. Femora covered by black setae dorsally, some few pale setae laterally. Claws unmodified. Pulvilli small. Leg I: CxI ( Fig. 2 ) largely covered with pale, fine setae, decreasing in length towards apex, basal ones longer and sinuous (MSSC); base of FI ( Fig. 2 ) with 2 pale, long posteroventral setae, and with anterior bush-like comb of brown setae (MSSC); tibia I covered by fine setae, longer dorsally; tarsus I ( Fig. 3 ) with ventral surface entirely bare, dorsal surface covered by pale setae; tarsomere 1 longer than sum of remaining tarsomeres, ventrally swollen at basal 1/3 (all MSSC). Leg II: CxII with few pale setulae anteriorly, bare laterally; FII ( Fig. 4 ) with anterodorsal row of strong brown setae along apical 2/3, decreasing in length towards apex, ventral surface completely bare, except for anteroventral row of pale setae along basal 3/4, decreasing in length towards apex, and 1 sinuous, brown anteroventral seta (all MSSC); tibia II ( Fig. 4 ) with anterior row of brown setae, strongly curved medially (MSSC), 1 small, brown ventral apical seta. Leg III: CxIII with conspicuous, long, pale seta near base, and 2 pale setulae anteriad; FIII with dorsal row of black setae, decreasing in length towards apex; tibia III with 1 dorsal brown seta at distal 1/4, and comb of pale ventral setulae apically, upper to tarsal excavation (MSSC); IIIt1 with ventral excavation at base (MSSC). Abdomen: Mostly brown, with some dark blue reflections on T4–5. T1–5 covered by short black setae. Segment 6 hidden under T5, T6 bare; segment 7 forming short peduncle, T7 and S7 bare; S8 small, triangular. S1–3 visible, sclerotized, S4 membranous. Hypopygium ( Figs. 5–7 ): Epandrium elongate, twice longer than high, dark. Epandrial lobe elongate, digitiform, with 2 small dorsal setae at apex. DSur and VSur enlarged, placoid, covering internal appendages and phallushypandrium; VSur twice higher than DSur, with 2 internal setae at apex. Pair of hook-like lateral projections of VSur ending at mesal, sharp unpaired sclerite ( Fig. 6 ). Hypandrium basally fused to epandrium. Phallus with short dorsal projection near apex. Cercus rounded and covered by fine setae, with digitiform projection apically with spine ( Fig. 6 ). Pair of internal appendages next to cercus bearing curved seta at apex ( Fig. 6 ). Female: Body length: 2.9–3.3 mm. Wing: 2.5–2.9 mm long, 0.9–1.1 mm wide. Habitus similar to male, except by MSSC and as noted. Head: Face slightly broader than in males (about as broad as ocellar tubercle), slightly wider towards apex, clypeal suture evident; first flagellomere shorter. Wing ( Fig. 11 ): Spurious veins on R4+5 and M much shorter, fewer in number and restricted to distal parts of veins than in males, no spurious veins on dm-cu; R4+5 and M converging distally, M ending at apex; R4+5 only slightly concave on distal half, not as close to margin as in males; M bent anteriorly on distal third; CuA1 reaching wing margin. Legs: I: 2.4, 2.0, 1.2, 0.7, 0.4, 0.3, 0.3; II: 3.0, 2.5, 1.9, 0.9, 0.5, 0.3, 0.2; III: 2.9, 3.4, 1.0, 1.2, 0.6, 0.4, 0.3. Mostly dark yellow to pale brown. Cx II and III dark brown; trochanters pale brown; femora yellow to pale brown; tibia I pale brown, II and III yellow, base and tip of II and III infuscated; tarsi brown, base of II and III yellow. CxI covered by scattered black setulae anteriorly. Ventral surface of FII bare and scarcely infuscated. Tibia II: 1 anterior seta near middle, 1 posterodorsal seta at base, 2 ventral setae at basal and apical 1/3, 1 anterodorsal, 1 anteroventral and 1 ventral setae at apex; tibia III: row of 5–7 short dorsal setae. Abdomen: T1–5 with short vestiture of black setae dorsally, almost bare laterally. Sternites light brown, covered by few black setae, S5 darker. Oviscapt ( Figs. 8–9 ) telescoped into pre-segments, T10 flattened, prolonged and fused to cerci, acanthophorite dorsal with spines at apex.

Etymology. From the Tupi-Guarani native Brazilian language, “pepo” (wing) and “catu” (beautiful), referring to conspicuous wing vein pattern.

Comments. Mberu is known up to now only from the type-locality ( Cabo Verde, State of Minas Gerais, Brazil). This is a relatively high area in the Atlantic Forest (around 600 m, with surrounding mountains reaching 1200 m) and Malaise traps have been kept for six years in this patch of forest near a creek, with steep slopes on both sides. It is noteworthy that the occurrence of male secondary sexual modifications in less intense extend in females has been reported in only a few dolichopodid species from different subfamilies, as wing patterns in Hydrophorus titicaca Becker (Hydrophorinae) and Amblypsilopus zonatus (Parent) (Sciapodinae) ( Bickel 1994), and leg chaetotaxy of Medetera dorrigensis Bickel (Medeterinae) ( Bickel 1987). Bickel (1994: 26) provided an interesting brief summary on how these kinds of characters could work in a genetic perspective.

Figures

FIGURES 1 – 4. Mberu pepocatu gen. nov. et sp. nov.: male. 1, habitus. 2, fore coxa and femur (permanent slide). 3, fore tarsus (permanent slide). 4, mid femur and tibia (permanent slide). Scale bars: 0.5 mm.

FIGURES 5 – 7. Mberu pepocatu gen. nov. et sp. nov.: male hypopygium. 5, left lateral view. 6, right lateral view, but reflected (right cercus removed). 7, ventral view. Scale bar: 0.1 mm. See Material and methods for explanation of abbreviations.

FIGURES 8 – 9. Mberu pepocatu gen. nov. et sp. nov.: female oviscapt. 8, dorsal view. 9, left lateral view. Scale bar: 0.1 mm. See Material and methods for explanation of abbreviations.

FIGURES 10 – 11. Mberu pepocatu gen. nov. et sp. nov.: wings (permanent slide). 10, male. 11, female. Scale bar: 1.0 mm. See Material and methods for explanation of abbreviations.