Plecia macrocephala ( 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 : 30-32

Plecia macrocephala ( Heyden & Heyden, 1865) (figs. 44–47, 140–143)

Protomyia macrocephala Heyden & Heyden 1865: 23 .

Protomyia schineri Heyden & Heyden 1865: 27 . Syn.n.

Plecia ♂ Nr. 10 Statz 1943: 34.

Plecia ♂ Nr. 11 Statz 1943: 34.

Localities: Rott.

Material examined: Holotype Protomyia macrocephala (female) NHMUK 58794 (fig. 44) . Holotype Protomyia schineri (male) NHMUK In 58798 (fig. 45) .

Additional material: Males: STIPB A 564, LACMIP 2533.264ab/LACMIP Type 3394 (fig. 46). Females: LACMIP 2533 1073, STIPB A 229, A 232, A 235, A 558, Siegburg Rott-640, Rott-943.

Description:

Female (N=8, figs. 44, 140–141): Total length 7.8–9.2 mm (N=5).

Head (fig. 141): Length 0.83–0.91 mm (N=3), width 0.82–1.20 mm (N=5). Dark brown, relatively large, square, with prominent, angular corners. Complex eye rather large, not protruding. Antenna: robust, cylidrical, flagellum 0.46–0.57 mm long (N=2), 0.14 mm wide (N=1), probably 8-segmented.

Thorax (fig. 141): Length 2.0– 2.5 mm (N=5), width 1.7–2.1 mm (N=3). Dark brown, haltere dark brown?

Wing: Length 6.9–8.1 mm (N=5), width 2.3–2.9 mm (N=4), length/width = 2.7–3.0 (N=4). Light brown fumose. Veins light brown, little contrasting against membrane. Costal cell somewhat darkened. Pterostigma small, oval, fairly distinctive. Humeral vein absent? Costa extends to apex of R 4+5. Subcosta indistinctive. R 2+3 oblique, R 4+5 apically gently curved. R-M vertical. Posterior veins not possible to see in holotype. Vein measurements are given in Table 4 .

Legs: Brown, slender, not well preserved in any of the specimens at hand. Fore femur length 2.0 mm, width 0.34 mm (N=1), fore tibia length 1.8–1.9 mm (N=2), width 0.24 mm (N=1), fore first tarsomere length 0.9 mm (N=1), hind tibia length 2.8 mm (N=1), hind first tarsomere length 1.0 mm (N=1).

Abdomen: Length 5.0– 6.9 mm (N=5), width 2.1–2.5 mm (N=4). Brown, spindle-shaped. Last tergite gently concave. Cerci small, rounded.

Male (N=3, figs. 45–46, 142–143): Total length 8.5 mm (N=1). Brownish-black, legs light brown, wing light brownish fumose.

Head: Length 1.08–1.19 mm (N=2), width 0.97–1.22 mm (N=2). Brown. Antenna rather slender, flagellum 8- segmented, 0.44 mm long, 0.08 mm wide (N=1).

Thorax: Length 2.0– 2.5 mm (N=6), width 1.5–2.2 mm (N=4). Reddish brown.

Legs: Light reddish brown, slender. Fore femur length 1.6 mm (N=1), fore tibia length 1.6–2.3 mm (N=4), width 0.24–0.26 mm (N=2), first fore tarsomere length 0.7–1.0 mm (N=2), hind femur length 1.9–2.8 mm (N=3), width 0.38–0.42 mm (N=2), hind tibia length 2.0– 3.1 mm (N=3), width 0.24–0.29 mm (N=3), first hind tarsomere 0.8–1.0 mm (N=3).

Wing: Length 5.2–7.5 mm (N=7), width 2.0– 2.5 mm (N=7), length/width = 2.5–3.0 (N=7). Slender, little pigmentation preserved in the specimens at hand, veins fine and brown. Humeral vein present, vertical. Subcosta fine, straight, running well clear of R. Pterostigma invisible. Costa terminates at apex of R 4+5. R 2+3 oblique, rather straight. R 4+5 apically nearly straight. R-M slightly oblique. CuA-veins apically rather strongly curved basad. Vein measurements are given in Table 4.

Abdomen: brown, cylindrical, rather long and slender.

Terminalia (fig. 143): Hypopygium rectangular in outline. Gonostyli attached laterally, very robust.