Plecia lygaeoides (Heer, 1849)

(Figs. 7, 27)

Bibio lignarius Germar, 1837 sensu Unger, 1841: 427 (nec Germar), pro parte

Protomyia lygaeoides Heer, 1849: 232.

Plecia lygaeoides (Heer) Loew, 1868: 185.

Penthetria lygaeoides (Heer) Evenhuis, 1994: 129.

Protomyia latipennis Heer, 1849: 237 (syn.n.)

Plecia latipennis (Heer) Loew, 1868: 184.

Penthetria latipennis (Heer) Handlirsch, 1907: 960.

Type material: Holotype (female) SLJG 77465. Type and depicted specimen, P. latipennis (female), SLJG (no number). The latter specimen is also labeled as Rhipidia extincta Unger, but this must be a mistake since the specimen does not at all fit the original description of Rhipidia extincta.

Additional material: Female (CNHM 1833).

The type specimen was redescribed by Skartveit & Nel (2017: 51).

The species is habitually similar to Penthetria cimicoides, but easily distinguished from this species by the short vein R 2+3.

Female: Total length 10.1–10.2 mm (N=2)

Head: Length 1.2 mm (N=1), width 1.1 mm (N=2). Width Black, poorly preserved.

Thorax: Length 2.4–2.6 mm (N=3), width 2.1–2.4 mm (N=2). Black.

Wing (Fig. 27): Length 9.3–10.3 mm, width 3.4–3.8 mm, length/width = 2.7–2.9 (N=3). Dark brown fumose, relatively wide. Costa distinctively curved, costal cell wide. Subcosta relatively weak. R 2+3 oblique, with a slight bend in the middle. Pterostigma oval, not very distinctive. Costa extends a little beyond apex of R 4+5. Wing vein measurements: basal R 2.7–3.0 mm (N=3), distal R 1 3.1–3.8 mm (N=3), basal R s 1.7 –1.8 mm (N=3), distal R s 1.5 –1.8 mm (N=3), R 2+3 1.0– 1.2 mm (N=3), R 4+5 2.7–3,0 mm (N=3), R–M 0.5 mm (N=2), basal M 3.0 mm (N=1), distal M 0.9–1.1 mm (N=2), M 1 3.7 mm (N=1), M 2 3.2 mm (N=2), CuA 2.2–2.5 mm (N=2), CuA 1 4.5 mm (N=1), CuA 2 3.2 mm (N=1).

Legs: Black, slender. Fore tibia length 2.4 mm (N=1). Hind femur length 2.8 mm (N=1), slightly thickened, hind tibia 2.8–3.2 mm (N=3), tibia and tarsus quite slender.

Abdomen: Length 6.8–6.9 mm (N=2). Black, oval, poorly preserved in P. latipennis type, covered by wings in P. lygaeoides type.

The species has been recorded from both Radoboj and French Oligocene sites (Skartveit & Nel, 2017). Given that these sites are now thought to be more than 10 MYr older than Radoboj, it seems questionable if the two species are the same. Should they be found to be different, the Radoboj species will keep the name Plecia lygaeoides whereas the French Oligocene species should be called Plecia gracilenta (Heyden & Heyden, 1865).