Periscelis, Winertzii Egger, 1862

Roháček, Jindřich & Andrade, Rui, 2017, Periscelis fugax sp. nov., an overlooked European species of Periscelididae (Diptera), with notes on the morphology and terminology of terminalia, Acta Entomologica Musei Nationalis Pragae 57 (1), pp. 229-251 : 248-249

Key to identification of the Palaearctic taxa of the subgenus Periscelis s. str.

1 Wing with membrane unicolorous; posterior cross-vein (dm-cu) absent. .................. 2

– Wing with fumose cloudings; posterior cross-vein (dm-cu) developed ( Fig. 2 ). ....... 4

2(1) Larger species (body length more than 4 mm). Antennal pedicel (not scape) blackish brown. Ventral part of face yellow, whitish microtomentose and with 5–6 pairs of setae. Mesonotum grey microtomentose with a pair of longitudinal brownish microtomentose vittae. A pair of strong prescutellar ac setae (situated in front of posterior dc) present. Male genitalia with robust elongately triangular surstylus, short subtriangular gonostylus ( PAPP & WITHERS 2011: Fig. 1 ) and cercus large, broad and with long setae. ......................................................................................... P. annulipes Loew, 1858

– Smaller species (body length distinctly less than 3 mm). Pedicel pale brown, ochreous yellow basally. Ventral part of face brown, grey microtomentose and with only 1 pair of setae. Mesonotum dark grey, with pale grey microtomentum. No prescutellar ac. Male genitalia with very slender and long surstylus, elongately subtriangular gonostylus, and cercus more slender but with robust setae ( PAPP & WITHERS 2011: Figs 6, 7 ). ..................................................................................................................................... 3

3(2) Gonostylus longer, hence surstylus less than 1.4 times as long as gonostylus ( PAPP & WITHERS 2011: Fig. 5 ); ejacapodeme more robust and proximally not widened ( PAPP & WITHERS 2011: Figs 3 , 6 ). ........................................ P. nigra nigra (Zetterstedt, 1860)

– Gonostylus shorter, hence surstylus about 1.6 times as long as gonostylus ( PAPP & WITHERS 2011: Figs 7 , 14 , 15 ); ejacapodeme more slender and proximally dilated ( PAPP & WITHERS 2011: Figs 7, 9 ). ............................... P. nigra minor Papp & Withers, 2011

4(3) Antennal pedicel with blackish spot on outer side extended laterally up to ventral margin ( Fig. 5 ). Mesonotum medially unicolorous grey ( Fig. 5 ) or with brown vittae only indicated ( Fig. 33 ); scutellum all dark or with yellow restricted to apex ( Figs 5 , 34 ). Male S6 widened posteriorly, brown pigmented along anterior and lateral margins, simple posteromedially ( Fig. 22 ). Gonostylus more slender and with apex bent anteriorly ( Fig. 26 ); postgonite distally more robust but its broad proximal part not extended posteroventrally ( Fig. 25 ). Female T8 posteromedially pale-pigmented, darker only laterally ( Fig. 29 ); S8 narrowly brown only laterally and less densely setose ( Fig. 30 ). ........................................................................................ P. winnertzii Egger, 1862

– Antennal pedicel with blackish spot smaller, laterally reaching to about half of its outer side ( Fig. 4 ). Mesonotum medially with distinct pair of brown vittae ( Fig. 3 ); scutellum with largely or entirely yellow disc ( Fig. 3 ). Male S6 suboblong, not widened posteriorly, brown pigmented only laterally and with narrow medial depression ( Fig. 13 ). Gonostylus shorter and thicker, with apex simple ( Fig. 9 ); postgonite distally more slender and broad proximal part produced posteroventrally ( Fig. 8 , arrow). Female T8 uniformly brown pigmented ( Fig. 16 ); S8 narrowly brown laterally and posteriorly and more densely setose ( Fig. 17 ). ........................................................... P. fugax sp. nov.

Figures

Figs 1–2. Periscelis (P.) fugax sp. nov. 1 – male holotype, body length ca 3.4 mm; 2 – wing, length 3.1 mm, male paratype (Portugal: Valongo). Photo by J. Roháček.

Figs 6–10. Periscelis (P.) fugax sp. nov., male paratype (Portugal: Valongo). 6 – entire genitalia, laterally; 7 – surstylus, laterally; 8 – postgonite, laterally; 9 – gonostylus, sublaterally (widest extension); 10 – cercus, laterally.Scale = 0.1 mm. For abbreviations see p. 231.

Figs 3–5. Periscelis species. 3 – Periscelis (P.) fugax sp. nov., male paratype, body dorsally, length ca 3.0 mm (Czech Republic: S. Moravia); 4 – same specimen, laterally; 5 – Periscelis (P.) winnertzii Egger, 1862, male, head and thorax subdorsally, body length ca 4.1 mm (Hungary). Photo by J. Roháček.

Figs 11–14. Periscelis (P.) fugax sp. nov., male paratype (Portugal: Valongo). 11 – external genitalia caudally (surstyli omitted); 12 – same, cranially (cerci omitted); 13 – pregenital sternum (S6), ventrally; 14 – aedeagal complex, laterally (only basal part of distiphallus depicted). Scale = 0.1 mm. For abbreviations see p. 231.

Figs 15–21.Periscelis (P.) fugax sp. nov., female paratype (Portugal:Valongo). 15 – postabdomen, dorsally; 16 – T8, dorsally; 17 – S8, ventrally; 18 – spermathecae; 19 – ventral receptacle, laterally; 20 – 5th segment and postabdomen, ventrally; 21 – posterior part of postabdomen (from 7th segment), laterally. Scales = 0.2 mm (Figs 15, 20, 21) and 0.1 mm (Figs 16–19). For abbreviations see p. 231.

Figs 33–34. Periscelis (P.) winnertzii Egger, 1862, female (Slovakia), body length ca 4.2 mm. 33 – living adult, laterally; 34 – same specimen, dorsally. Photo by J. Roháček.

Figs 22–27. Periscelis (P.) winnertzii Egger, 1862, male (Hungary). 22 – pregenital sternum (S6), ventrally; 23 – ejacapodeme, laterally; 24 – surstylus, laterally; 25 – postgonite, laterally; 26 – gonostylus, sublaterally (widest extension); 27 – cercus, laterally. Scales = 0.1 mm. For abbreviations see p. 231.

Figs 28–32. Periscelis (P.) winnertzii Egger, 1862, female (Hungary).28 – 5th segment and postabdomen, ventrally; 29 – T8, dorsally; 30 – S8, ventrally; 31– ventral receptacle, laterally; 32 – spermathecae. Scales = 0.2 mm (Fig. 28) and 0.1 mm (Figs 29–32). For abbreviations see p. 231.