Revision of fossil Bibionidae (Insecta: Diptera) from French Oligocene deposits
Author
Skartveit, John
Author
Nel, André
text
Zootaxa
2017
4225
1
1
83
journal article
37263
10.5281/zenodo.259087
05be601b-f9f1-4952-ac09-7012ef31aab0
1175-5326
259087
4676EE59-569B-4197-B108-9B32FD88E68E
Plecia foersteri
Théobald, 1937
(
Figs. 25
–
28, 119
–
122)
Plecia Försteri
Théobald, 1937
: 136
.
Plecia splendida
Théobald, 1937
: 137
Syn.
n.
Plecia oviformis
Théobald, 1937
: 229
. Syn.n.
Plecia rubescens
(
Oustalet, 1870
)
sensu
Théobald 1937
: 230
.
Material examined.
Holotype (female) of
Plecia foersteri
NMB F1390. 4 paratypes (females) of
Plecia foersteri
NMB F
1391-1394
. Lectotype (female, herein designated) of
Plecia splendida
NMB F1396. Paratype (female) of
Plecia spendida
NMB F1397. Paratype (female) of
Plecia splendida
MNHN B 23563. Holotype (female) of
Plecia oviformis
NMB F1384.
Théobald (1937: 137 and 231)
described
Plecia splendida
with two “holotypes” (should be syntypes), one from Kleinkembs and the other one from Célas. We have studied the former but did not succeed in locating the latter, which may be lost. A species cannot have two holotypes, to clarify the identity of this species we have designated the one of the “holotypes” which could be found as a lectotype. The holotype of
Protomyia rubescens
is not recognizable, as was also commented on by
Théobald (1937)
. He therefore (presumably) designated a “hypotypoide” for “
Plecia
cf.
rubescens
” (NHMB F1395/1), this specimen has no type status but is useful in clarifying Théobald’s concept of the species.
Additional material (28 females): NMB F1395/1, F1410, F1411/1-22, F1412, F2048, F2175, F2223, F2368.
Localities.
Kleinkembs, Ronzon, Célas.
Diagnosis.
A small-medium sized
Plecia
(wing length
4.9–7.8 mm
). Antennal flagellum 8-segmented. Thorax black, abdomen brown, wing light brownish fumose.
Redescription.
Male unknown. There is one male specimen (NHMB F 2090) in NHMB labelled as
Plecia
cf.
rubescens
, but it is highly uncertain if this is conspecific with the females.
Female: Total length
6.2
–
8.5 mm
(N=23).
Head (figs. 120, 122): Length
0.59
–
0.78 mm
(N=12), width
0.63
–
0.96 mm
(N=15). Rather short and broad, oval, compound eye prominent. Antenna length
0.41
–
0.62 mm
(N=8), rather short and thick, flagellum 8- segmented. Ocellar tubercle small.
Thorax: Length
1.7
–
2.7 mm
(N=27), width 1.4
–
2.0 mm (N=16). Black. Sulci deep and distinctive. Haltere brown.
Wing (fig. 119): Length 5.4
–
8.0 mm (N=26), width
1.9
–
3.2 mm
(N=23), length/width = 2.10
–
2.87 (N=23). Light brownish fumose, veins brown. Subcosta long and distinctive, humeral vein present.
Costa
extending to apex of R4+5. R2+3 slightly curved, oblique. Fork of M rounded. Pterostigma indistinctive. Wing vein measurements in Table 2.
Legs: Brown, slender.
FIGURES 119–122.
Plecia foersteri
Théobald, 1937
Fig. 119. Female, wing. NMB F1411/22.
Fig. 120
. Female, head and thorax, dorsal. NMB F2423.
Fig. 121
. Female, terminalia, ventral. NMB F1411/13.
Fig. 122
. Female, head and thorax, NMB F1390.
Abdomen: Brown, spindle-shaped.
Terminalia: Cerci short and indistinctive.