Penthetria lugens ( Oustalet, 1870 )

Skartveit, John & Nel, André, 2017, Revision of fossil Bibionidae (Insecta: Diptera) from French Oligocene deposits, Zootaxa 4225 (1), pp. 1-83 : 31-32

Penthetria lugens ( Oustalet, 1870)

( Figs. 14 – 15, 95 – 97)

Protomyia lugens Oustalet, 1870: 142 – 143.

Plecia cf. lugens ( Oustalet, 1870) ; Théobald, 1937: 227. Penthetria lugens ( Oustalet, 1870) ; Handlirsch, 1908: 959.

Material examined. Holotype (female) MNHN R 0 6666.

Additional material: 2 females (MNHN B 24412, B 24518). 5 females (NHB F2208, F2230, F2323, F2410, F2413). 1 female (FSL 391923).

Localities. Corent, Céreste, Kleinkembs

The holotype specimen (fig. 12) is in very poor condition, wing venation and most details are impossible to see. Collomb et al. (2008) classified the type as Insecta, incerta sedis, though it is recognizable as a Plecia or Penthetria female. However, the diagnostic appendages on gonapophysis VIII are visible, confirming that the holotype is conspecific with Penthetria lugens sensu Théobald, 1937 .

Diagnosis. A medium-sized, slender Penthetria . Body brownish, wings brown fumose. R2+3 slightly sinuous and oblique. On ventral side of abdomen gonapophysis VIII has a pair of digitiform appendages.

Redescription. Male unknown

Female (fig. 13) Total length 8.3 – 11.5 mm (N=4).

Head (fig. 96): Length 0.93 – 1.11 mm (N=3), width 1.01 – 1.27 mm (N=3). Dark brown, probably black in life. Antennal flagellum probably 5- or 6-segmented.

Thorax: Length 2.0 – 2.6 mm (N=4), width 2.0 mm (N=2). Dark brown, probably black in life. Haltere yellowish-brown.

Wing (fig. 95): Length 8.6 – 9.4 mm (N=4), width 2.9 – 3.3 mm (N=4), length/width = 2.87 – 3.34 (N=4). Brown fumose, R-veins brown, posterior veins concolourous with membrane. Costa extends nearly to apex of M1. Humeral vein present, Subcosta fine and short, terminating well before crossvein R-M. Pterostigma indistinctive. R2+3 with a bend in basal third, otherwise nearly straight, oblique. R4+5 apically nearly straight. Posterior veins not possible to see in specimens at hand. Wing vein measurements in Table 1 .

Legs: Brown, slender. Fore femur 2.0 mm (N=1), fore tibia 2.2 mm (N=1), hind femur 2.6 mm (N=1), hind tibia 2.7 mm (N=1).

Abdomen: Length 6.1 – 7.6 mm (N=4), width 1.7 – 2.9 mm (N=3). Light brown, relatively long and narrow, spindle-shaped.

Terminalia (fig. 97): Gonapophysis VIII with a digitiform appendage on each side. Cerci two-segmented, relatively long.

Fig. 96 . Female, head and thorax, dorsal. FSL 391923. Fig. 97 . Female, terminalia, ventral. NMB F2413.

Figures

FIGURES 95 – 97. Penthetria lugens (Oustalet, 1870) Fig. 95. Female, wing. NMB F 2410.