Periscelis (Myodris) annulata ( Fallen , 1813)

Pollini Paltrinieri, Lucia & Rohacek, Jindrich, 2022, Periscelis (Myodris) haennii sp. nov., a new species of Periscelididae (Diptera) from Ticino, Switzerland, with a new key to European species of the subgenus, Alpine Entomology 6, pp. 39-49 : 39

Periscelis (Myodris) annulata ( Fallen, 1813)

Figs 5 , 9 , 17-22 , 27-30 , 36

Redescription of male genitalia.

Epandrium (Figs 17 , 20 , 22 ) small, shortly arch-shaped, distinctly higher than long (Fig. 17 ) but almost as broad as high (Fig. 22 ), with large (although slightly narrower than that of P. (M.) haennii ) anal opening. Setae on epandrium relatively long but subequal in length and distributed only in posterior marginal area surrounding anal opening. Surstylus (Fig. 21 ) long, proximally broad but relatively suddenly (see somewhat angular anterobasal part) distally tapered. This slender distal part of surstylus slightly bent, provided with a row of fine setulae at anterior margin (Fig. 21 ) and with relatively acute apex. Cerci free and inserted below anal opening as in relatives. Each cercus slender and elongate but shorter than height of anal opening (see Figs 20 , 22 ), tapered distally, with apex slightly bent anteriorly (Fig. 18 ) and provided with a pair of distinctly separate short anteroapical spines; posterior and posterolateral sides of cercus with some micropubescence and a row of long setae, the apical and (often) also subapical which are longer than others (see Fig. 18 ). True gonostylus lost; medandrium (see Fig. 20 , ma) extremely reduced, forming a small transverse sclerite attached to posterior part of hypandrium. Hypandrium (Fig. 17 ) frame-shaped and relatively well separated from (dorsally attached) phallapodeme as characteristic for all Myodris species, without any trace of pregonites. Aedeagal complex very large, composed of large pocket-shaped phallapodeme, very long and slender submembranous aedeagus and distinctly sclerotized paired postgonites. Phallapodeme (Fig. 17 ) formed as in P. (M.) haennii , thus pocket-shaped and compact (= without separate basal part). Aedeagus (Fig. 17 ) also very similar (both in form and length, and formed only by distiphallus) to that of the latter species but its membranous apex rather spindle-shaped. Postgonite (Fig. 19 ) relatively large and distally slender, slightly longer than surstylus (cf. Fig. 17 ), with basal part short and broad, with distal slender part gradually tapered, straight and somewhat shorter than that of P. (M.) haennii having acute apex and a row of setulae at posterior margin. Ejacapodeme (Fig. 17 ) robust but relatively simple, basally hardly wider than distally, shorter and less elongate (about 4.5 times as long as its maximum width) than that of P. (M.) haennii .

Figures

Figures 4 - 10. Periscelis (Myodris) species, adults. 4. P. (M.) haennii sp. nov., male paratype (dried from ethanol), thorax dorsally; 5. P. (M.) annulata (Fallen), male (dry mounted), thorax dorsally; 6. P. (M.) piricercus Carles-Tolra & Verdugo Paez, male (dried from ethanol), thorax dorsally; 7. P. (M.) haennii sp. nov., male paratype (dried from ethanol), laterally; 8. P. (M.) haennii sp. nov., male paratype, right wing; 9. P. (M.) annulata (Fallen), male, right wing; 10. P. (M.) piricercus Carles-Tolra & Verdugo Paez, male, right wing. Only Fig. 5 is based on specimen from Slovakia, others are from specimens from Losone (Switzerland). All scales: 0.5 mm. Photos by J. Rohacek.

Figures 17 - 22. Periscelis (Myodris) annulata (Fallen), male genitalia (Slovakia). 17. Entire genitalia, laterally; 18. Cercus, laterally; 19. Aedeagal complex, laterally (only basal parts of distiphallus, phallapodeme and hypandrium depicted); 20. External genitalia cranially (setosity of epandrium and cerci largely omitted); 21. Surstylus, laterally; 22. External genitalia caudally. For abbreviations see p. 41. Scales: 0.05 mm (18); 0.1 mm (17, 19 - 22).

Figures 23 - 34. Male S 6 and structures of genitalia of European Periscelis (Myodris) species. 23 - 26. P. (M.) haennii sp. nov., paratype: 23. S 6; 24. Cercus laterally; 25. Surstylus laterally; 26. Postgonite laterally; 27 - 30. P. (M.) annulata (Fallen), Slovakia: 27. S 6; 28. Cercus laterally; 29. Surstylus laterally; 30. Postgonite laterally; 31 - 34. P. (M.) piricercus Carles-Tolra & Verdugo Paez, Switzerland: 31. S 6; 32. Cercus laterally; 33. Surstylus laterally; 34. Postgonite laterally. Scales: 0.05 mm (24, 28, 32); 0.1 mm (23, 25 - 27, 29 - 31, 33, 34).

Figures 35 - 36. Distal part of male abdomen of two Periscelis (Myodris) species (photographed in situ in ethanol). 35. P. (M.) haennii sp. nov., paratype; 36. P. (M.) annulata (Fallen), Switzerland. Scales: 0.1 mm. Photos by L. Pollini Patrinieri.