Bibio aerosus 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 : 40-41

Bibio aerosus Statz, 1943 (figs. 62–63, 174–176)

Bibio areosa Statz, 1943: 50 .

Bibio spadicea Statz, 1943: 51 . Syn.n.

Bibio aerosus Statz. Evenhuis 1994: 122 (Spelling emendation)

Localities: Rott

Material examined: Holotype (female) of Bibio aerosa LACMIP 2533.232 / LACMIP Type 3362 (fig. 62). Holotype (female) of Bibio spadicea LACMIP 2533.244ab / LACMIP Type 3374 (fig. 63).

Description:

Female (N=2, figs. 62–63, 174–176):

Total length 10.5 mm (N=1)

Head (fig. 176): Length 1.6 mm (N=1). Relatively long, ocellar tubercle not prominent. Antenna stout, flagellum probably 7-segmented, 0.73 mm long, 0.24 mm wide (n=1).

Thorax (fig. 176): Length 3.4 mm (N=1). Dark brown, haltere reddish-brown.

Legs: Fore leg dark brown, protibia 1.7 mm long (N=1), robust with very short spur. Hind tibia 2.7 mm long, 0.5 mm wide (N=1), pale with brown apex, slender, spur very short. Hind tarsus brown, slender.

Wing (fig. 175): Length 6.5–7.3 mm, width 2.7–3.2 mm, length/width = 2.2–2.4 (N=2). Relatively short and broad, light brown fumose, veins brown, distinctive throughout, radial veins with dark brownish shading. Pterostigma oval, dark brown, small but distinctive. Subcosta straight , fine and indistinctive, humeral vein not apparent. Costa extends to apex of R 4+5. Basal Rs about three times as long as R-M. Fork of M rather narrow, M-veins apically straight. Crossvein dM-Cu meets M 2 some distance apicad of furcation. CuA 1 strong, straight, CuA 2 weaker, apically bent. CuP straight, rather weak and indistinctive. Vein measurements are given in Table 5 .

Abdomen: Length 6.8–6.9 mm, width 2.4–2.5 mm (N=2), cylindrical, dark brown. Last tergite apically with wide, U-shaped indentation. Cerci small, rounded and indistinctive.

Male unknown.

Discussion:

Statz (1943) described Bibio aerosa and B. spadicea from one female specimen each. The type specimen of Bibio spadicea is rather poorly preserved, only one wing and the abdomen are reasonably visible. However those characters that can be observed are very similar to the type of Bibio aerosa .