Penthetria nervisinuata Theobald 1937, comb.n.
Creators: name: Skartveit, John
name: Nel, André
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Bibionidae
Penthetria
Penthetria nervisinuata

description: Penthetria nervisinuata (Théobald, 1937) comb.n.
(Figs. 16 – 17, 98 – 102)
Plecia nervisinuata Théobald 1937: 407
Bibiopsis funebris Heer in Heer & Gaudin, 1861: 153. (nec Penthetria funebris Meigen, 1804) (nomen nudum)
A medium-sized Penthetria, rather stocky for the genus, entirely black as usual for the genus. The shape of vein R2+3 is characteristic: it is vertical at base, then turns 90° and runs parallel to R4+ 5 in the basal half, then turns forwards, meeting Costa at an almost 45° angle.
Material examined. Holotype, female, FSL 391925 (fig. 14) from Aix. Paratype, female, FSL 391926.
Paratype, female, MNHN B 24519 from Céreste. Female, attributed by Heer to Bibiopsis funebris Heer (ETHZ 164).
Localities. Aix-en-Provence, Céreste.
Fig. 99. Female, head and thorax, dorsal. ETHZ Aix 164. Fig. 100. Female (?), wing, RGL Céreste 192.
Fig. 101. Male, terminalia, dorsal. MNHN Aix 981. Fig. 102. Male, wing. MNHN Aix 974.
Other material (MNHN): Males: Aix 779, 884, 974, 1085, P26. Females: Aix 332, 428, 645, 752, 799, 890, 926, 965, 1013, 1061, 1322, 1337, 1347, 1404. (RGL) Céreste 662. Isolated wing: Céreste 192. Female, labeled 164 (ETHZ, fig. 15).
Diagnosis. The species is easily recognized by the long, horizontal vein R2+3, which is sharply bent basally and a bit sinuous in the middle. It is the only species in the French Oligocene material with a typical Penthetria wing venation. Specimens with preserved pigmentation are entirely dark with blackish-fumose wings.
Redescription. Male: Total length 8.2 – 12.0 mm (N=5). The specimens are of a uniform, brown colour, probably not original colour.
Head: Length 0.96 – 1.30 mm (N=5), width 1.03 – 1.41 mm (N=4). Antenna robust, segments not possible to count.
Thorax: Length 2.2 – 2.9 mm (N=5), width 1.7 mm (N=1, smallest specimen).
Wing (fig. 102): Length 6.7 – 9.1 mm (N=4), width 2.2 – 2.9 mm (N=3), length/width = 2.98 – 3.30 (N=3). No pigment preserved in membrane, R-veins brown, posterior veins colourless. Costa extends to apex of R4+5. Humeral vein present, Subcosta terminating at origin of R2+3. Pterostigma oval, brown. R2+3 long, originating at base of pterostigma, bent in a right angle near base. Wing vein measurements in Table 1.
Legs: Slender, first tarsomere of hind leg slightly swollen and spindle-shaped. Fore femur 2.2 mm (N=1), fore tibia 2.2 – 2.3 mm (N=2), hind femur 2.7 – 3.5 mm (N=3), hind tibia 2.5 – 3.8 mm (N=3).
Abdomen: Length 5.4 – 8.0 mm (N=5), width 1.1 – 1.6 mm (N=2). Cylindrical.
Terminalia (fig. 101): Gonostylus digitiform, curved, pointed. Epandrium wide, dome-shaped. Hypopygium width 0.83 – 1.15 mm (N=4), gonostylus length 0.43 mm (N=1).
Female: Total length 7.5 – 12.0 mm (N=16). Holotype and one paratype very dark, probably the original colour. Most of the other specimens have little or no pigment preserved.
Head (fig. 99): Length 0.77 – 1.16 mm (N=11), width 0.82 – 1.28 mm (N=17). Rounded. Compound eye medium-sized, slightly protruding. Ocellar triangle prominent but not very tall. Antenna robust, flagellum probably 8-segmented.
Thorax: Length 1.9 – 3.1 mm (N=16), width 1.7 – 2.6 mm (N=15). Sulci prominent. Haltere dark brown.
Wing (figs. 98, 100): Length 7.0 – 10.5 mm (N=18), width 2.7 – 3.9 mm (N=16), length/width = 2.44 – 3.00 (N=14). Blackish fumose, R-veins dark, posterior veins concolourous with membrane. Costa terminates at apex of R4+5. Humeral vein present, Subcosta terminating at or slightly beyond origin of R2+3. Pterostigma oval, black. CuAveins conspicuously strong. Vein R2+3 long and sinuous, basally vertical, bent 90° and then running parallel to R4+5 before bending toward costa in distal half. Relative length of stem and fork of CuA apparently quite variable. CuA2 apically curved basad. Wing vein measurements in Table 1.
Legs: Slender, covered with short erect dark pile. Length of fore femur 2.0 – 2.6 mm (N=5), fore tibia 1.8 – 2.6 mm (N=6), hind femur 2.1 – 3.1 mm (N=5), hind tibia 1.9 – 3.5 mm (N=6).
Abdomen: Length 5.1 – 8.3 mm (N=14), width 1.9 – 2.8 mm (N=13). Cylindrical.
Terminalia: Three spermathecae present. Cerci two-segmented, small and slender.
description: Published as part of Skartveit, John & Nel, André, 2017, Revision of fossil Bibionidae (Insecta: Diptera) from French Oligocene deposits, pp. 1-83 in Zootaxa 4225 (1) on pages 32-34, DOI: 10.5281/zenodo.259087