A new fossil species of the genus Bibio, with an update on bibionid flies from Baltic and Rovno amber (Diptera, Bibionidae)
Author
Skartveit, John
https://orcid.org/0000-0001-7614-3399
NLA University College Bergen, P. O. Box 74 Sandviken, N- 5812 Bergen, Norway
john.skartveit@hotmail.com
text
Deutsche Entomologische Zeitschrift
2021
2021-01-27
68
1
81
99
http://dx.doi.org/10.3897/dez.68.60611
journal article
http://dx.doi.org/10.3897/dez.68.60611
1860-1324-1-81
2AD03B672D3B4B03A37359854A506F3E
E49FE28F84D353F6ADDF2598DB8661F2
Plecia clavifemur Skartveit, 2009: 15-16
Fig. 4
Type material, females.
Holotype, SDEI Dip-00830 - CCHH#1474.2. Paratypes SDEI Dip-00845 - CCHH#1505.1; SDEI Dip-00846 - CCHH#1501.5.
Additional material, females.
JS-Baltic-002, in piece of amber 20
x15x
4 mm
, JS-Baltic-003, in piece of amber 18
x13x
6 mm
. These specimens do not reveal any characters not seen in the
type
material, but their morphometric data is given below.
Total length
3.47-4.62 mm
.
Head: Length
0.42 mm
(N = 1), width
0.57-0.60 mm
. Flagellum length
0.40-0.47 mm
, width
0.08 mm
(N = 2).
Thorax: Length
0.83-0.92 mm
.
Legs: Fore femur
0.66-0.79 mm
long,
0.12-0.15 mm
wide, fore tibia
0.75-1.11 mm
long,
0.08-0.09 mm
wide, fore first tarsomere
0.24-0.38 mm
long,
0.05-0.07 mm
wide, fore second to fifth tarsomeres 0.19, 0.13, 0.11 and
0.15 mm
long (N = 1). Mid femur
0.88 mm
long,
0.15 mm
wide (N = 1), mid tibia
0.69 mm
long,
0.08 mm
wide (N = 1). Hind femur
0.90-1.24 mm
long,
0.11-0.15 mm
wide, hind tibia
0.97-1.20 mm
long,
0.08-0.12 mm
wide, hind first tarsomere
0.23-0.41 mm
long,
0.07-0.09 mm
wide.
Wing: length
3.05-3.11 mm
, width 1.00-
1.39 mm
, length/width = 2.24-3.05. Vein lengths, all in mm: Subcosta 1.50-1.58, basal R 1.00-1.13, distal R1 0.75-0.85, Rs 0.27-0.38, R2-5 0.58-0.83, R2+3 0.16-0.23, R4+5 0.64-0.68, R-M 0.07-0.17, basal M 0.92-1.05, distal M 0.33-0.34, M1 1.20-1.37, M2 0.88-1.00, M-CuA 0.11 (N = 1), CuA 0.67-0.79, CuA1 1.12-1.54, CuA2 0.58-1.16.
Abdomen: Length
2.5 mm
(N = 1).
Discussion.
The two specimens examined are similar in the shape of the head and antenna, general aspects of wing venation (short R2+3, kinked R4+5, CuA2 bent sharply basad) and terminalia, however they are rather different with respect to some morphometric traits, particularly length of leg segments and the general shape of the wing. At the present state of knowledge I interpret this difference as within intraspecific variation, though additional material, particularly if male specimens are found, may reveal that there are more than one species involved.
Figure 4.
Plecia clavifemur
, female. JS-Baltic-003. Photo: Jonas Damzen.