Stegana Meigen, 1830

Pirani, Gabriela & Grimaldi, David A., 2019, Rediscovery, redescription, and reclassification of the rare and unusual fly Pyrgometopa penicillata Kertész (Diptera: Drosophilidae), Zootaxa 4661 (3), pp. 445-456 : 446-447

Genus Stegana Meigen

Meigen, 1830: 79; Grimaldi (1990) revised diagnosis; Bachli et al. (2004) European species; Brake & Bachli (2008) world catalogue. Type species: S. nigra Meigen, 1830 ; Zetterstedt 1847: 2577 (= S. furta Linneaus, 1766 ). AF, AU, NE, NT, OR, PA.

Pyrgometopa Kertész, 1901: 419 . Type species: P. penicillata Kertész . Monotypic. New Synonym. NT

Diagnosis: Wing held against side of body at rest ( Fig. 2 , 7 ); apex bluntly pointed, veins R 4+5 and M 1 convergent, apices nearly touching, parallel at apex; C with row of minute, thorn-like spinules at apex ( Fig. 31–32 ). Mid tarsomeres 1–4 with 2 ventral rows minute, overlapping, scale-like setulae ( Figs. 34 ); hind tarsomeres 1–4 with one or two such rows ( Figs. 33, 34 ). Hypandrial complex very elaborate; phallapodeme usually long, fused to phallus and postgonites. Phallic guide usually present.

Comments: Pyrgometopa has all the above-mentioned characters, fitting entirely in the definition of Stegana . The latter genus is cosmopolitan and more diverse in the tropical regions of the world. Furthermore, we have some undescribed species with modifications on the frons and ocellar tubercle that also fit entirely within Stegana and it is probable that they all form a clade within the genus.

Figures

FIGURES 1–6. Stegana penicillata (Kertész) new combination from Peru. 1. Female: frontal view of head (face). 2. Female: lateral habitus. 3. Female: dorsal view of head and thorax. 4. Female: lateral view of head. 5. Male: lateral view of head. 6. Male: wing. Abbreviations. bm: basal medial cell, br: basal radial cell, cua: anterior cubital cell, CuA: anterior branch of cubita, CuA + CuP: anterior branch of cubital vein + posterior branch of cubital vein, dm: discal medial cell, dm-m: discal medial croossvein, h: humeral crossvein, M1:first branch of media, M4: fourth branch of media,R1: anterior branch of radius, R2+3: second branch of radius, R4+5: third branch of radius,r-m: radial medial crossvein, Sc: subcostal vein. Scale bars: 0.5 mm.

FIGURES 7–11. S. penicillata female from French Guiana. 7. Lateral habitus. 8. Dorsal habitus. 9. Dorsal view of head (frons). 10. Frontal view of head (face). 11. Lateral view of head. Scale bars: 0.5 mm.

FIGURES 25–32. Scanning electron micrograph (S.E.M) of S. penicillata. 25. Frontal view of head (face). 26. Ocellar tubercle. 27. Apex of bristles on ocellar tubercle. 28. Ventral view of labellum. 29. Frons. 30. Antenna: first flagellomere and arista. 31. Apex of wing. 32. Spine on wing apex;

FIGURES 33–35. Scanning electron micrograph (S.E.M) of leg and its spines of S. penicillata. 33. Hind leg. 34. Line of spines on first tarsomere. 35. One of the spines in detail, arrow pointing to a pollen grain of Vernonia sp.