Bibio curtisii Heer, 1856

Skartveit, John & Nel, André, 2017, Revision of fossil Bibionidae (Insecta: Diptera) from French Oligocene deposits, Zootaxa 4225 (1), pp. 1-83 : 64-66

Bibio curtisii Heer, 1856

(Figs. 56 – 61, 178 – 183)

Bibio curtisii Heer 1856: 34 – 35.

Bibio martinsi Heer in Heer & Gaudin, 1861: 153 (nomen nudum) Bibio ungeri marginatus Oustalet, 1870: 125 . Syn.n. Bibio romani Théobald, 1937: 336 Syn. n.

Bibio serresi Théobald, 1937: 336 Syn. n.

Material examined. Lectotype (herein designated) male NHMUK In 39833. This specimen was illustrated by Murchison & Lyell (1829) and later by Heer (1856, Fig. 14). Specimen NHMUK In 39855 is the counterpart of the lectotype. Paralectotypes (males, herein designated) NHMUK In 39825/39845 (part and counterpart), ETHZ S.N. 158 (part and counterpart). Holotype (female) of Bibio romani (FSL 391915). Paratype (male) of Bibio serresi (FSL 391905). Bibio ungeri v. marginatus (depicted specimen, male, Théobald 1937) FSL 391918, A 26, (female) FSL 391919, A38, (female) FSL 391920, A 87, (female) EEFN Coll. Fliche F 201.

Fig. 179. Female, wing. ETHZ Aix.

Fig. 180. Male, head and thorax. NHMUK In 39833. Fig. 181. Male, fore leg. NHMUK In 39825. Fig. 182. Male, hind leg. NHMUK In 39825. Fig. 183. Male, terminalia, dorsal. MNHN Aix 1062.

Other material: 1 male (ETHZ S.N. 131), 1 male (FSL 391904), 3 males (MNHN Aix 42, Aix 54, Aix 584), one pair of wings, presumably male (ETHZ S.N. 137), 2 females (FSL 391908, 391909), 4 females (ETHZ S.N. 131), 2 females (MNHN Aix 873, Aix 950), 1 female (MNHN B 24431).

While Bibio ungeri marginatus is synonymous with this species, Bibio ungeri s.str. is obviously another species entirely. A specimen in the Museum of Natural History, Vienna is a Penthetria species, while Heer’s figure ( Heer 1849: Plate XVI: 8) is of a specimen in Landesmuseum Joanneum, Graz which is obviously not a bibionid. This large and slender specimen, which is rather poorly preserved with head and legs missing, is apparently a brachyceran, and possibly belongs in Xylophagidae or Asilidae . The wing venation is hard to see but apparently there is a pointed anal cell and a closed discal cell in the wing.

Localities. Aix-en-Provence.

Diagnosis. A medium-sized-large Bibio (9.5 – 12 mm). Head normal-sized for genus, antennal flagellum sevensegmented. Male compound eye with conspicuous, long, dark pile. Wing hyaline with dark brown veins, humeral crossvein present between Sc and Costa in basal third, pterostigma black, conspicuous. Crossvein R-M short but distinctive. Veins CuA1 and CuA2 apically distinctively curved. Legs all black. The species is habitually rather similar to Bibio crassinervis Skartveit & Pika, 2014 from the Miocene site of Öhningen, but differs from that in having an obvious humeral crossvein, which is absent in B. crassinervis , as well as having the wing veins not quite as strong and prominent.

Redescription. Male: Total length 8.5 – 11.6 mm (N=30)

Head (fig. 180): Length 1.43 – 1.87 mm (N=9), width 1.64 – 1.97 mm (N=7). Compound eye with dense and rather long, brownish pile. Antennal flagellum probably 7-segmented. Palp robust.

Thorax: Length 2.9 – 3.8 mm (N=10), width 2.4 – 2.8 mm (N=3). Black, dorsally with long, dark pile. Haltere dark brown.

Wing (fig. 178): Length 6.3 – 7.9 mm (N=11), width 2.6 – 3.5 mm (N=11), length/width = 2.38 – 2.65 (N=11). Hyaline to light brownish, veins blackish, prominent throughout. Humeral vein prominent. Pterostigma brown, oval, prominent. Costa terminates just after apex of R4+5. Basal part of Radial sector about three times as long as R- M. Crossvein M-Cu joins M2 slightly beyond fork of M. CuA1 apically curved backwards. Wing vein measurements in Table 4 .

Legs (figs. 181–182): Dark brown, presumably black in life. Protibia with spine about three times as long as spur. Hind femur moderately stout and clavate, hind tibia evenly expanding towards apex, not conspicuously clavate, with short, robust spur. Hind tarsus slender. Fore femur 1.7 – 2.3 mm long (N=3), 0.55 – 0.72 mm wide (N=3), fore tibia 1.4 – 1.7 mm long (N=2), hind femur 2.4 – 3.6 mm long (N=7), 0.47 – 0.66 mm wide (N=7), hind tibia 2.7 – 3.7 mm long (N=5), 0.50 – 0.58 mm wide (N=5), hind first tarsomere 0.9 – 1.0 mm (N=2).

Abdomen: Length 5.6 – 6.9 mm (N=10), width 1.6 – 2.0 mm (N=5). Dark brown, presumably black in life.

Terminalia (fig. 183): Epandrium 0.97 – 1.16 mm wide (N=5), with wide, shallow, U-shaped emargination, lateral lobes short and blunt. Gonostylus robust, of the typical shape for the genus.

Female: Total length 10.0 – 12.0 mm (N=6).

Head: Length 1.08 – 1.22 mm (N=3), width 1.05 – 1.30 mm (N=2). Antennal flagellum 7-segmented.

Thorax: Length 2.9 – 3.8 mm (N=6), width 2.6 – 2.7 mm (N=2). Dark brown, presumably black in life.

Haltere brown.

Wing (fig. 179): Length 7.8 – 9.9 mm (N=6), width 3.2 – 3.5 mm (N=5), length/width = 2.44 – 2.82 (N=5). Light brownish hyaline, veins strong and blackish throughout, pterostigma blackish. Venation as in male. Wing vein measurements in Table 4 .

Legs: Dark brown, presumably black in life. Hind femur robust, clavate, hind tibia slender. Fore femur length 1.8 – 2.3 mm (N=5), width 0.59 – 0.77 mm (N=3), fore tibia length 1.8 – 2.3 mm (N=4), hind femur length 2.4 – 3.2 mm (N=4), width 0.54 – 0.64 mm (N=4), hind tibia length 2.5 – 3.2 mm (N=5), width 0.32 – 0.43 mm (N=3).

Abdomen: Length 6.7 – 8.4 mm (N=6), width 2.3 – 2.9 mm (N=3). Dark brown, presumably black in life. Parallel-sided, the two terminal tergites narrower. Cerci prominent, pointed.