Plecia rhenana Heyden & Heyden, 1865

Skartveit, John & Wedmann, Sonja, 2021, A Revision of fossil Bibionidae (Insecta: Diptera) from the Oligocene of Germany, Zootaxa 4909 (1), pp. 1-77 : 35-36

Plecia rhenana Heyden & Heyden, 1865 (figs. 55, 158–159)

Plecia rhenana Heyden & Heyden 1865: 28–29 .

Localities: Rott. Also in Aix-en-Provence, France.

Female redescribed by Skartveit & Nel (2017).

Material examined: Holotype (female) NHMUK In 38798 (fig. 55).

Description:

Female (N=1, figs. 55, 158–159):

Total length 9.1 mm.

Head ( fig.159 ): Length 1.01 mm, width 1.01 mm, complex eye rather large and flat. Antenna slender, flagellum 0.65 mm long, 0.15 mm wide, 8-segmented.

Thorax: Length 2.5 mm, width 2.0 mm, dark brown, haltere dark brown.

Legs: Slender. Just apical part of tibia and tarsus of fore and mid legs preserved. Tibiae apparently pale, tarsi dark brown. Fore tibia 1.9 mm long.

Wing ( fig. 158 ): Length 9.3 mm, width 3.3 mm, length/width = 2.8. Light brownish fumose, rather narrow and a little pointed. Veins brown, pterostigma oval, brown, quite distinctive. Humeral vein present. Subcosta running close to R but distinctive. Costa extends to a little beyond apex of R 4+5. R 2+3 oblique, gently, evenly curved. R 4+5 apically gently curved. R-M vertical. Fork of M asymmetrical, rounded. CuA 2 apically distinctly curved basad. CuP fine, curved, running some distance from CuA and parallel to this vein. Vein measurements are given in Table 4.

Abdomen: 5.8 mm long, 2.4 mm wide.

Discussion:

This name obviously has meant different things to different authors. Plecia rhenana sensu Statz is not P. rhenana Heyden & Heyden. It differs from the holotype in having darkened, not hyaline, wings, being much larger and having a pseudovein along CuA.The holotype female has a wing length of 9.3 mm, whereas a specimen of Plecia rhenana sensu Statz is a very large Plecia with a wing length of 13.7 mm.

Figures

FIGS. 156–157 Plecia proserpina FIG. 156. Female, habitus. NHMUK 58793. FIG. 157. Female, wing. LACMIP 2533.285. FIGS. 158–159. Plecia rhenana FIG. 158. Female, wing. NHMUK In 38798. FIG. 159. Female, head and thorax. NHMUK In 38798.