Plecia clavifemur Skartveit, 2009: 15-16

Skartveit, John, 2021, A new fossil species of the genus Bibio, with an update on bibionid flies from Baltic and Rovno amber (Diptera, Bibionidae), Deutsche Entomologische Zeitschrift 68 (1), pp. 81-99 : 81

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 ×15× 4 mm, JS-Baltic-003, in piece of amber 18 ×13× 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.

Figures

Figure 4. Plecia clavifemur, female. JS-Baltic- 003. Photo: Jonas Damzen.