Plecia exigua Statz, 1943

Skartveit, John & Wedmann, Sonja, 2021, A Revision of fossil Bibionidae (Insecta: Diptera) from the Oligocene of Germany, Zootaxa 4909 (1), pp. 1-77 : 24-25

Plecia exigua Statz, 1943 (figs. 27–29, 114–118)

Plecia exigua Statz, 1943: 26

Plecia Ƌ Nr. 13 Statz, 1943: 35.

Plecia ♂ Nr. 14 Statz, 1943: 36.

Localities: Rott.

Material examined: Syntypes (females) LACMIP 2533.269ab / LACMIP Type 3401 (part and counterpart), 2533.270ab / LACMIP Type 3402 (part and counterpart).

Additional material, males: LACMIP 2533.256/LACMIP Type 3386, LACMIP 2533.266 / LACMIP Type 3396, LACMIP 2533.1242, 2533.1243, 2533.1255, 2533.1272, 2533.1312

Description:

Female (N=2, figs. 27, 114–116):

Total length 4.4–4.9 mm (N=2)

Head (fig. 116): Length 0.60 mm (N=1), width 0.56–0.72 mm (N=2), rather large and wide, complex eye protruding, ocellar triangle large. Antenna with flagellum 0.44 mm long, 0.11 mm wide (N=1), cylindrical, 7-segmented (?).

Thorax: Length 1.3 mm (N=2), width 1.1 mm (N=1) brown with three dark brown vittae. Haltere light brown.

Legs: Only one front leg preserved. Fore femur 1.1 mm long, 0.28 mm wide, fore tibia 1.2 mm long, 0.16 mm wide, first fore tarsomere 0.56 mm long (N=1). Femur light yellowish brown with dark tip, tibia and tarsus dark brown.

Wing (fig. 115): Length 4.6–4.9 mm (N=2), width 1.9 mm, length/width = 2.6 (N=1). Light brownish fumose, veins brown and fine. Humeral vein absent? Subcosta fine and straight. Costa extends to about half-way between apices of R 4+5 and M 1. R 2+3 rather short, oblique, gently and evenly curved. R 4+5 apically slightly curved. R-M vertical. M-veins and CuA-veins apically nearly straight. Vein measurements are given in Table 4.

Abdomen: Length 2.7–2.9 mm, width 1.2–1.3 mm (N=2), brown, spindle-shaped, rather stout.

Male (N=9, figs. 28–29, 117–118):

Total length 4.5–6.5 mm (N=9)

Head: Length 0.79–1.04 mm (N=6), width 0.69–0.94 mm (N=5). Dark brown. Antenna flagellum 7-segmented, 0.08–0.14 mm long (N=5). Ocellar tubercle small but prominent.

Thorax: Length 1.3–1.9 mm (N=8), width 1.1–1.4 mm (N=5). Dark brown, haltere light brown.

Legs: Fore and mid-femora pale yellowish, distal third dark brown, hind femur pale yellowish, dark brown in extreme tip, fore and mid tibiae and tarsi dark brown, hind tibia light brown, hind tarsus brown. Hind tibia with rather long, fine, curved spur, about one-third length of first tarsomere.

Wing (fig. 118): Length 3.7–5.4 mm (N=9), width 1.4–2.0 mm (N=6), length/width = 2.5–3.1 (N=6). Light brown fumose, rather narrow. Veins brown throughout. Pterostigma oblong-oval, brown, indistinctive. Humeral vein present but weak, oblique. Subcosta running very close to R for most of its length. Costa extends to apex of R 4+5. R 2+3 short, nearly vertical, curved. R 4+5 apically gently curved. R-M slightly oblique. Fork of M asymmetrical, veins gently curved. CuA-veins apically nearly straight. CuP rather weak, straight. Vein measurements are given in Table 4.

Abdomen (fig. 118): Brown, slightly conical. Hypopygium with rounded sides. Gonostylus attached laterally, robust.