Bibiodes provincialis, Skartveit, John & Nel, André, 2017

Skartveit, John & Nel, André, 2017, Revision of fossil Bibionidae (Insecta: Diptera) from French Oligocene deposits, Zootaxa 4225 (1), pp. 1-83 : 75

Bibiodes provincialis sp. n.

(figs. 69 – 70, 207 – 211)

Material examined. Holotype (male) MNHN Aix 1079. The specimen is preserved lying on the side, but with abdomen twisted so that the terminalia can be seen as if from dorsal view. Paratypes: males: MNHN Aix 62, 676. Females: MNHN Aix 23, 543, 959.

Localities. Aix-en-Provence

Diagnosis. A medium-small (5.5 – 7.5 mm) bibionid, though relatively large for the genus. Antenna stout, flagellum possibly 5-segmented. Hind tibia strongly clavate. Male gonostyli are simple and digitiform.

Description. Male: Total length 5.5 – 7.0 mm (N=3). The specimens have head and thorax brown, legs and abdomen pale brown, no pigmentation preserved in wings.

Head (fig. 208): Length 0.97 – 1.24 mm (N=3). Ocellar triangle tall and prominent. Compound eye without conspicuous pile, lower section prominent. Antenna stout, flagellum possibly 5-segmented, 0.63 mm long (N=1).

Thorax: Length 2.0 – 2.8 mm (N=3). Brown.

Wing: Length 4.3 – 5.8 mm (N=3), width 1.7 – 2.5 mm (N=2), length/width = 2.37 – 2.50 (N=2)). Apparently hyaline. Few details discernible in specimen at hand. Wing vein measurements in Table 5 .

Legs: Protibia with long spine. Hind femur and tibia strongly clavate. Hind tarsus swollen. Length of fore tibia 1.2 – 1.5 mm (N=2), fore first tarsomere 0.9 mm (N=1), hind femur 1.6 – 2.5 mm (N=3), width 0.31 – 0.50 mm (N=3), hind tibia 1.5 – 2.4 mm (N=3), width 0.37 – 0.50 mm (N=3), hind first tarsomere 0.7 mm (N=1).

Abdomen: Length 3.8 – 4.0 mm (N=3). Pale brown.

Terminalia (fig. 211): Hypopygium width 0.57 – 0.86 mm (N=2). Epandrium bilobate, lobes rounded, indentation between them widely U-shaped. Gonostylus length 0.31 mm (N=1), digitiform.

Female (fig. 209): Total length 6.0 – 7.5 mm (N=3). All specimens are preserved as relief impressions with little or no preserved colouration.

Head: Length 0.81 – 0.83 mm (N=1), width 0.81 – 0.93 mm (N=2). Relatively short and broad. Ocellar triangle prominent. Compound eye rounded, length approximately half length of head. Antenna stout, flagellum 0.5 mm long (N=1), possibly 5-segmented.

Thorax: Brown. Length 1.8 – 2.5 mm (N=3), width 1.9 mm (N=1).

Wing (fig. 207): Length 5.2 – 6.5 mm (N=3), width 2.0 – 2.7 mm (N=3), length/width = 2.11 – 2.64 (N=3). Veins fine, Costa extends slightly beyond apex of R4+5. Veins R s and M are merged for a distance about twice the length of basal section of Rs. Pterostigma not apparent. Wing vein measurements in Table 5 .

Legs (fig. 210): Protibia with ventral tubercle and long spine. Hind tibia clavate, hind tarsus swollen. Fore femur length 1.3 – 1.6 mm (N=2), width 0.4 – 0.7 mm (N=2). Fore tibia length 1.2 – 1.8 mm (N=2). Hind femur length 1.7 – 2.3 mm (N=2), width 0.37 – 0.49 mm (N=2), hind tibia length 1.6 – 2.1 mm (N=2), width 0.29 – 0.39 mm (N=2). Hind first tarsomere 0.5 – 0.8 mm (N=2).

Abdomen: Cylindrical. Length 3.9 – 4.7 mm (N=3), width 1.8 – 2.1 mm (N=2).

Terminalia: Not clearly visible in any of the specimens at hand.