Penthetria gracilis ( Unger, 1842 ) Skartveit & Krizmanić, 2020

Skartveit, John & Krizmanić, Katarina, 2020, Revision of fossil Bibionidae (Insecta: Diptera) from the Miocene of Radoboj, Croatia, Zootaxa 4759 (3), pp. 351-378 : 355-356

Penthetria gracilis ( Unger, 1842) comb.n.

( Figs. 3 , 22–23 )

Bibio gracilis Unger, 1842: 426 . (nec Protomyia gracilis Heer, 1856 )

Type material: Holotype (male, SLJG 77464 ). Heer (1849: 217) mentioned one specimen from Graz and one from Vienna. There is a male specimen in NHMW labeled « Bibio ungeri Heer » which is clearly not conspecific with the holotype of Bibio ungeri , this could possibly be the second specimen.

Male: Total length 11.2 mm

Head: Length 1.21 mm, width 1.32 mm. Black, very poorly preserved.

Thorax: Length 3.2 mm, width 2.4 mm. Black. Halter yellowish-brown.

Wing ( Fig. 22 ): Length 7.4 mm, width 3.3 mm. Dark brown fumose, veins strong throughout, dark brown, pterostigma indistinctive. Costa quite straight, subcosta indistinctive. Costa extends a little over half-way between apices of R 4+5 and M 1. R 2+3 straight and oblique. M-veins and CuA 1 apically straight. CuA 2 apically curved. Vein measurements: basal R 2.4 mm, distal R 1 3.2 mm, basal R s 1.2 mm, distal R s 1.3 mm, R 2+3 1.4 mm, R 4+5 2.9 mm, R-M 0.4 mm, basal M 2.8 mm, distal M 0.6 mm, M 1 3.5 mm, M 2 2.8 mm, M-Cu 0.3 mm, CuA 2.0 mm, CuA 1 3.8 mm, CuA 2 2.5 mm.

Legs: Black, poorly preserved. Length of fore femur 2.3 mm, hind femur 3.3 mm.

Abdomen: Length 7.3 mm, width 1.7 mm. Black, rather slender. Pile not apparent.

Terminalia ( Fig. 23 ): Hypopygium width 1.2 mm. Gonostylus digitiform, slender and curved. Epandrium moderately bilobate with wide, shallow indentation between rounded lobes.

Female unknown.

The species is not to be confused with Protomyia gracilis Heer, 1856 (placed as a synonym of Plecia bucklandi by Skartveit & Nel 2017), which was listed as Penthetria gracilis by Handlirsch (1907) and Evenhuis (1994).

Figures

FIGURE 3. Penthetria gracilis, male, holotype, SLJG 77464.

FIGURES 22–25. 22. Penthetria gracilis, male, wing, SLJG 77464. 23. Penthetria gracilis, male, hypopygium, dorsal view, SLJG 77464. 24. Penthetria longa, male, wing, NHMW, no catalog number. 25. Penthetria murchisonii, female, holotype, wing, SLJG 77466. Scale bar = 1 mm.