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
Bibiodes
sp.
(
Fig. 212
)
This species is represented by a single female specimen.
Material
.
NMB F
2136
(
1
female)
Localities.
Kleinkembs
Diagnosis.
The single female specimen is not well enough preserved to be reliably separated from
B. provincialis
,
but the antenna appears to be more slender, and the section where veins Rs and M are fused appears to be shorter than in
B. provincialis
.
Description.
Male unknown.
Female: Total length
6.5 mm
(N=1).
FIGURES 207–211.
Bibiodes provincialis
sp. n.
Fig. 207. Female, wing. MNHN Aix 23.
Fig. 208
. Male, head and thorax. MNHN Aix 1079.
Fig. 209
. Female, habitus. MNHN Aix 959.
Fig. 210
. Female, hind leg. MNHN Aix 23.
Fig. 211
. Male, terminalia. MNHN Aix 1079.
FIGURE 212.
Bibiodes
sp., female, habitus. NMB F2136.
FIGURES 213–214.
Dilophus luteipennis
(Théobald, 1937)
Fig. 213. Female, wing. FSL 391913.
Fig. 214. Female, head and thorax. FSL 391913.
Head: Length
0.7 mm
(N=1). Black. Compound eye relatively small. Ocellar tubercle tall and prominent. Antenna not well preserved but appears to be relatively slender.
Thorax: Length
2.2 mm
(N=1). Black. Scutum strongly developed, relatively flat. Haltere dark reddish brown.
Wing: Length 6.0 mm, width
2.1 mm
, length/width = 2.92 (N=1). Hyaline, veins yellowish, pterostigma oval, light brown, distinctive.
Costa
extends slightly beyond apex of R4+5. Subcosta fine and indistinctive, humeral vein probably present. Radial sector and M merged for a short distance. M and CuA with relatively short stems and long forks. Wing vein measurements in
Table 5
.
Legs: Blackish-brown, presumably black in life, robust. Fore femur length
1.4 mm
, width
0.62 mm
, fore tibia length
1.5 mm
, with short, stout spur, less than one third as long as spine. Hind femur length
1.9 mm
, width
0.44 mm
, stout throughout, hind tibia length 2.0 mm, width
0.27 mm
, slender, first tarsomere slender.
Abdomen: Chestnut-brown, rather stout, cylindrical. Length
3.8 mm
(N=1).
Terminalia: The tergites of the last three segments are apparently missing, so the internal structures are uncovered. Genital fork and two spermathecae are clearly visible, but a third spermatheca may be partly hidden.
TABLE 5.
Bibiodes
and
Dilophus
spp., wing measurements
Measurement
|
B. provincialis
m
|
B. provincialis
f
|
D. luteipennis
f
|
Total length
|
4.3-5.8 (3) |
5.2-6.5 (3) |
3.8-4.5 (2) |
Total width
|
1.7-2.5 (2) |
2.0-2.7 (3) |
1.5-1.7 (2) |
MA-First branch of R
|
1.4 (1) |
1.4-1.7 (2) |
0.9-1.2 (2) |
R
1
|
1.1 (1) |
1.5-2.0 (2) |
1.0-1.6 (2) |
R
s
|
0.8 (1) |
0.7-0.8 (2) |
0.4-0.6 (2) |
R
s
+M
|
0.23 (1) |
0.4-0.7 (2) |
N.A. |
R
4+5
|
- |
2.2-3.1 (2) |
2.0-2.7 (2) |
M basal to R-M
|
1.5 (1) |
0.9-1.4 (2) |
0.9 (1) |
M distal to R-M
|
- |
0.5-0.7 (2) |
0.6-1.1 (2) |
M
1
|
- |
1.9-2.2 (2) |
1.5-1.7 (2) |
M
2
|
- |
1.7-2.1 (2) |
1.3-1.5 (2) |
R-M
|
N.A. |
N.A. |
0.22-0.36 (2) |
M-Cu
|
- |
0.30-0.49 (2) |
- |
CuA
|
- |
1.0-1.3 (2) |
- |
CuA
1
|
- |
2.4-3.4 (2) |
- |
CuA
2
|
- |
1.9-2.2 (2) |
- |
Genus
Dilophus
Meigen, 1803
|
Dilophus luteipennis
(Theobald,
(Fig. 71, 213
–
214)
|
1937) comb.n.
|
Bibio luteipennis
Théobald, 1937: 333
.
|
Material examined.
Holotype (female) of
Bibio luteipennis
FSL 391913 (A 16). Paratype (female) of
Bibio luteipennis
FSL 391914 (A 86).
Localities.
Aix-en-Provence.
Diagnosis.
A medium-sized
Dilophus
, 5.5
–
6.0 mm. Mesonotum black, pleurae yellowish, legs yellowishbrown with black tarsi. Protibia possibly with three mesal spines. Wing hyaline with small, dark brown pterostigma.
Redescription.
Male unknown. There are several male
Dilophus
specimens from Aix-en-Provence in MNHN, but it is highly uncertain if these belong to
D. luteipennis
.
Female: Total length 5.5
–
6.0 mm (N=2).
Head (fig. 214): Length
0.7 mm
(N=1). Black. Antenna short and stocky, segments not possible to count in the specimens at hand.
Thorax: Length
1.3
–
1.5 mm
(N=2), width
1.4 mm
(N=1). Mesonotum black, pleura brownish-yellow. Spine rows not possible to see in the specimens at hand.
Wing (fig. 213): Length 4.0
–
4.6 mm
(N=2), width
1.5
–
1.8 mm
(N=2). Hyaline, pterostigma small, oval and dark brown, R-veins dark brown, posterior veins colourless.
Costa
extends to apex of R4+5.Crossvein R-M slightly longer then basal part of R s. Wing vein measurements in
Table 5
.
Legs: Yellowish-brown, tarsi black. Protibia rather stout, possibly with three mesal spines. Hind femur
1.3 mm
, hind tibia
1.2 mm
(N=1).
Abdomen: Length
3.7
–
4.4 mm
(N=2), width
1.5 mm
(N=1). Cylindrical, dark brown.
Terminalia: Cerci rather long, apically blunt, slightly hooked.