ggg Syrphidae. 



1901. Verr. Brit. Fl. VIII, 363, 11, fig. 290. — 1907. Kat. palaarkt. Dipt. 

 III, 64. — Scaeva rihesii p. p. 1817. Fall. Dipt. Suec. Syrph. 40. 



Male. Vertex somewhat elongate, brownish yellow pruinose; frons 

 yellow and yellow pruinose, with a black lunulate spot above the 

 antennæ, shining in front, dull behind. Epistoma yellow, whitish 

 pruinose towards the sides. Vertex and frons black-haired ; epistoma 

 rather densely yellow-haired, above at the sides of the antennæ are 

 black hairs. Jowls yellow. Occiput yellowish grey, the hairs white 

 below, yellow upwards; above a row of black, overhanging hairs. 

 Eyes bare. Antennæ black; arista longer than the antennæ. Thorax 

 brass-coloured, slightly or moderately shining, somewhat dullish, but 

 fnuch less than in rihesii, in front with faint traces of three brown 

 stripes separated by two greyish lines, and it is slightly yellowish at the 

 sides; it is clothed with yellow or reddish yellow hairs, densest at the 

 sides. Scutellum yellow with black hairs, on the basal part more or fewer 

 yellow hairs, sometimes nearly all yellow-haired. Pleura yellow-haired. 

 Abdomen dull black, a little shining at the apex; it has yellow basal 

 spots and two broad bands; the basal spots are large, somewhat 

 triangular with the hind margin about stiaight; tliey are placed quite 

 near the front margin and not broadly separated in the middle; the 

 bands lie close to the front margins of the segments and are straight, 

 the one on third segment occupies the half of the segment and has 

 a little emargination just in the middle behind; the band on fourth 

 segment occupies less than the half of the segment and has no 

 emargination; the bands all go over the margin in fuU breadth; the 

 fourth segment has a broad, yellow hind margin, the fifth is almost 

 quite yellow. The hairs foUow mainly the ground colour, but are 

 black at the apex, and on the middle and at the hind margin of the 

 band on fourth segment; at the sides the hairs alternate yellow and 

 black in accordance with the bands. Venter yellow on the basal half, 

 brown or black on the apical half; it is clothed with long hairs, mainly 

 yellow on the basal, black on the apical part, but the basal part has 

 some black hairs behind. Genitalia small, yellow, only the knob a 

 little dark behind ; the hairs yellow and black. Legs yellow with the 

 base of femora black, anterior tarsi with the three middle joints 

 darkened, hind tarsi blackish, brownish towards base; front and hind 

 coxæ yellowish. The long hairs behind the anterior femora yellow, 

 somewhat dense on middle femora; the hairs on the anterior side of 

 hind femora not long, black with some few yellow below; the short 

 hairs mainly yellow on the anterior legs, black on the hind legs, but 

 middle femora often with many black hairs on the anterior side, and 

 hind tibiæ with yellow hairs below. Wings hyaline or a little tinged. 



