Syrphus. 277 



1. S. albostriatus Fall. 



1817. Fall. Dipt. Suec. Syrph. 42, 10 (Scaeva). — 1822. Meig. Syst. 

 Beschr. III, 317, 63. - 1843. Zett. Dipt. Scand. II, 727, 29 et 1849. VIII, 

 3141, 29 (Scaeva). — 1862. Schin. F. A. I, 304. — 1901. Verr. Brit. Fl. 

 VIII, 344, 1, figs. 282-284. — 1907. Kat. palaarkt. Dipt. III, 57. — Syr- 

 phus confimis Egg. 1860. Verh. zool. bot. Gesell. V^ien, X, 664. — 1862. 

 Schin. F. A. I, 304. 



Male. Vertex greyish pruinose; frons and epistoma yellow, the 

 latter with a black middle stripe, stretching about to the antennæ; 

 the front mouth edge may be more or less darkened to black, this 

 colour sonietimes stretching as a band up to the eye; jowls yellow. 

 Vertex yellow-haired or just in front with some black hairs; frons 

 with black or yellow hairs, epistoma yellow-haired. Occiput grey 

 pruinose with yellow hairs, or some few black above. Eyes densely 

 pale-hairy. Antennæ blackish, the basal joints and the base below 

 on third joint more or less reddish or yellowish; arista longer than 

 the antennæ. Thorax æneous, shining, sonietimes a little purplish 

 and sometimes bluish; on the middle of the disc there are two ob- 

 vious, grey pruinose stripes, diverging behind, and here abbreviatcd; 

 humeri and præsutural depression yellow pruinose and postalar callus 

 yellow. Thorax yellow-haired. Scutellum yellow, generally more or 

 less darkened in the middle, with long, black, at the base more or 

 less yellow hairs, Pleura with yellow hairs. Abdomen black, dullish, 

 a little shining towards the apex; it has three pairs of yellow, oblique, 

 transverse spots, placed such that their outer ends are about the middle 

 of the side margins of the segments, while their inner ends are near the 

 front margins; the spots on third and fourth segments generally touching 

 in the middle, thus forniing arcuated bands; the spots are isolated 

 from the side margin. The hind margins of fourth and fifth segments 

 yellow, the latter segment also with yellow basal corners. The hairs 

 on abdomen mainly pale on the basal part, for the rest chiefly fol- 

 lowing the ground colour; all the hairs along the sides yellow. Venter 

 yellowish, pellucid, with black bands near the hind margins of the 

 segments; it is clothed with long, pale hairs. Genitalia not large, 

 black. Legs yellow with the base of anterior femora black, hind 

 femora with a broad, black ring, sometimes leaving only base and 

 apex yellow; hind tibiæ with a blackish ring on the middle, and hind 

 tarsi with the three last joints blackish. Often the anterior femora 

 are quite yellow and front coxæ more or less pale, hind femora with 

 a smaller ring and hind tibiæ quite yellow [confusus Egg.). The legs 

 are yellow-haired. Wings hyaline; stigma black. Squamulæ and 

 balteres pale yellow. 



