Cladochaeta nebulosa

Pirani, Gabriela & Amorim, Dalton De Souza, 2016, Going beyond the tip of the Drosophilidae iceberg: New Cladochaeta Coquillett, 1900 (Diptera: Drosophilidae) from Brazil, Zootaxa 4139 (3), pp. 301-344 : 334-338

nebulosa species group Grimaldi & Nguyen, 1999

Cladochaeta stigmata nov. sp.

( Figs. 30 A–F; 31 A–F; 17 B; 34 D; 36 C)

Diagnosis. Thorax light yellow, abdomen ochre; wing with infuscation over costal region and dm-cu crossvein; legs pale yellow to whitish; arista with only dorsal basal branch; phallus only partially sclerotized: broad bulbous membranous portion between two thin asymmetrical, sclerotized arms, membrane projected anteriorly, reaching phallapodeme medially.

Material examined. Holotype Ƌ: (Left wing and antenna slide-mounted, terminalia on vial), BRAZIL, State of São Paulo, Gália, E.E. Caetetus, 22º17’29”S 49º33’10”W, 12.iii.2010, Sweeping, Bertoni col. ( MZUSP). Paratype Ƌ: (terminalia on vial), BRAZIL, State of São Paulo, Serra do Japi, 18.iii.2010, Malaise trap, N.W. Perioto and team coll. ( MZUSP)

Description. Head ( Figs. 30 A–C). Higher than wide. Eyes bare, light red. Pedicel ochre, first flagellomere light ochre; arista curved downwards, with only basal dorsal branch ( Fig. 17 B). Frons pale yellow, ocellar triangle concolor. Fronto-orbital setae: anterior reclinate short, barely distinguishable from other fronto-orbitals, posterior reclinate slightly smaller than proclinate, closer to inner vertical than to proclinate; anterior reclinate slightly closer to proclinate than to posterior reclinate. Face flat, gena and face light ochre. Proboscis and palpus concolor with gena. Thorax ( Figs. 30 D–E). Light yellow. Anterior dorsocentral ca. ½ length of posterior dorsocentral. Posterior dorsocentral closer to scutoscutellar suture than to anterior dorsocentral. Acrostichals in 6 even rows. Basal and apical scutellars convergent. Three postpronotal setae, median longer than other two. Legs uniformily pale yellow. Wing ( Fig. 36 C). Length: 1.6 mm. Membrane infuscate, darker area extending from r2+3 cell to mid of r4+5 cell, gradually fading; small, rounded and diffuse cloud over r-m and a small darker cloud over dm-cu barely extending to CuA1. Tip of R2+3 curved towards wing margin. R4+5 and M parallel, tips slightly divergent. Crossvein dm-cu slightly sinuous, perpendicular to CuA1. Wing tip slightly acute. Halter whitish. Abdomen ( Fig. 30 F). All tergites ochre, posterior margins darker. Male terminalia ( Figs. 31 A–F). Epandrium inverted U-shaped, almost as high as wide, with 7 long setae on ventrolateral halves; ventral tip of ventrolateral halves gradually tapering, curved inwards terminally. Cercus with ventrolateral edges rounded, not extended. Phallus partially sclerotized: membranous portion broadly bulbous, placed between two thin asymmetrical sclerotized arms; membranous area projected anteriorly, reaching the phallapodeme medially; right sclerotized arm long, left shorter, both connected by a thin dorsal bridge. Phallapodeme thin, sinuous, heavily sclerotized. Surstylus simple, clavate; setae present on entire dorsal and dorsolateral surfaces of surstylus. Hypandrium Y-shaped, ventral keel present.

Etymology. The specific epithet comes from the Greek root stigma (mark), refering to the clouds of infuscation typical of the wing of this species.

Comment. This species was placed in the nebulosa species group due to the arista with a single dorsal basal branch, the clouded wing membrane, and the membranous, laterally flattened, median portion of the phallus, with a pair of asymmetrical, long and thin sclerotized arms. It closely resembles C. genuinus Grimaldi & Nguyen, 1999 on the morphology of phallus, clouding pattern of the wing and the sinuous dm-cu crossvein. However, C. genuinus has a long surstylus ventral lobe, absent in C. stigmata, nov. sp. and the proportional length of the left sclerotized arm of the phallus is different in both species as well.

Figures

FIGURE 17. Arista conditions in Cladochaeta. A. C. chauliodactyla nov. sp., holotype. B. C. stigmata nov. sp., holotype. Scale bars: 0.1 mm. Abbreviations: Ap. f.: apical fork; d- 1: first dorsal branch; d- 2: second dorsal branch; d- 3: third dorsal branch; d- 4: forth dorsal branch; dors. bas. br.: dorsal basal branch; vent. br.: ventral branch.

FIGURE 30. Cladochaeta stigmata, nov. sp., holotype. A. Head, dorsal view. B. Head, lateral view. C. Head, frontal view. D. Thorax, lateral view. E. Thorax, dorsal view. F. Abdomen, dorsal view. Scale bars: 0.1 mm.

FIGURE 31. Cladochaeta stigmata, nov. sp., holotype, male terminalia. A, D. Terminal view. B, E. Terminal oblique view. C, F. Lateral view.

FIGURE 36. Wings of Cladochaeta species. A. C. periotoi nov. sp. (holoype). B. C. phallotrixa nov. sp. (holotype). C. C. stigmata nov. sp. (holotype). Scale bar: 0.5 mm.