Tabanidae. 129 



12. T. autumnalis L. 



1761. Linn. Fn. suec. 462, 1883.— 1842. Zett. Dipt. Scand. I. 106, 2. 

 — 1862. Schin. F. A. I, 35. — 1880. Brauer, Denkschr. kais. Akad. Wis- 

 sensch. Wien, XLII, 192, 49. Tah. III et VI. Fig. 49. — 1903. Kat. palaarkt. 

 Dipt. II, 59. 



Male. Eyes dark, unicolorous ; eye-facets in the upper part, from 

 the apex of the frontal triangle, larger than below, the small facets 

 forming a rather broad band along the hind margin to the ocellar 

 tubercle. Face yellowish grey with pale yellow hairs, the cheeks with 

 black hairs. Frontal triangle yellow, apex brown. Anteimæ blackish 

 brown to black, the basal joint has the upper corner much produced. 

 Second joint of palpi long ovate, somewhat thicker towards the end 

 and then pointed. Thorax blackish brown, slightly shining, with five 

 greyish white stripes; clothed with blackish and yellowish golden hairs, 

 the latter with a tendency to form stripes ; pleura and sterna greyish 

 haired. Præalar callus generally rufous. Abdomen brownish red with 

 a broad, black dorsal line and, as a rule, the four last segments black, 

 but sometimes the reddish markings reach farther back; a row of 

 triangles in the dorsal middle line and a row of oblique spots on 

 each side greyish white; abdomen clothed with black and yellow 

 hairs, the latter clothing the triangles on the middle line and the 

 oblique spots on the sides; the hind corners of the segments also 

 pale and with pale hairs; seen from behind the pale haired spots are 

 silvergrey pruinose. Venter reddish brown, greyish pruinose, with a 

 black middle line and apex, the hind margins of the segments pale 

 and with pale hairs. Legs with the femora black; tibiæ yellowish 

 brown, the tips darkened, front tibiæ with the apical half or third 

 part black ; front tarsi black, posterior tarsi brownish. Femora clothed 

 with long, brownish grey hairs, tibiæ with short, partly dark hairs, 

 hind tibiæ with a fringe of black hairs on the outer side, sometimes 

 intermingled with some pale ones. Wings hyaline with brown veins. 

 Halteres with the peduncle brown and the knob whitish. 



Female. Eyes unicolorous. Frontal band rather narrow, greyish 

 yellow, frontal callus higher than broad, somewhat elliptical, prolonged 

 upwards in the linear middle callus. Second joint of palpi somewhat 

 thickened at the base, distinctly curved, produced in a rather long 

 point, whitish with whitish and black hairs. Abdomen somewhat flat. 

 black, the three rows of spots as in the male, but greyish white and 

 much more distinct on the black ground. Venter grey with a black 

 middle line. The tibiæ have more pale hairs than in the male, and 

 the fringe on the hind tibiæ has often niany pale hairs. 



Length 17,6—19 mm. 



9 



