278 Syrphidae. 



Female. Vertex and frons bluish, shining, but the anterior part, 

 above the antennæ yellow, on each side in the niiddle a large, yellow 

 pruinose side dust spot, united in the middle and thus forming an 

 arched band, cutting of an arched, transverse, bluish spot in front; 

 frons mainly dark-haired. Abdominal markings a little narrower than 

 in the male. 



Length 8,5— 10,5 mm. 



The larva answers mainly to Zeller's description; it is tlat, slightly 

 arched above; the derniis is coarsely but not densely chagreened, and 

 tho body is strongly, transversely corrugated; on the two first (the 

 meso- and metathoracal) segments are six small, conical warts on 

 each in a transverse row; the following seven segments have each at 

 the side margin three rather large, conical warts in a longitudinal 

 row; these segments have above one of the corrugations higher than 

 the others, and on the middle of this corrugation are two approximated 

 or almost fused warts, and to each side of them, a little more back- 

 wards, on the next corrugation, is a small wart, and more towards 

 the side a still smaller, rather indistinct wart; on the first of these 

 segments (first abdominal) the warts are all placed on the same 

 corrugation. The warts are fleshy; they are finely spined and each 

 terminates with a small spine, the side warts with a thread; the last 

 segment has two long, distant filaments at the hind margin; above 

 on this segment lies the brown or black posterior spiracular process, 

 which is nearly 1 mm long, divided in the apical third with the apices 

 diverging; each branch terminates at the apex on the inside in a 

 spine. The larva is grey or greyish brown, sometimes darker, and it 

 is somewhat marmorate from darker and paler markings, along the 

 dorsum is a row of more or less distinct, pale, dark contoured triangles, 

 one on each segment; they have the blunt apex turned forwards; for 

 the rest the markings form mainly more or less distinct, oblique 

 stripes on the sides of the segments, between the middle and side 

 warts; also a darker middle stripe may be present on the hind part. 

 The length of the fuU-grown larva is about 10 — 11 mm. The pupa is 

 similar to the larva, somewhat broad, the posterior part flat and not 

 attenuated; the warts and posterior filaments present as in the larva, 

 but shorter and more contracted; the colour mainly as in the larva. 

 The length of the pupa is about 7 mm. 



The thoracai stripes, the abdominal markings and the black stigma 

 easily distinguish this species. 



»S', albostriatus is not rare in Denmark; Copenhagen in gardens. 

 Amager, Ordrup Mose, Charlottenlund, Dyrehaven, Lyngby Mose, 

 Hillerød, Rørvig, Tisvilde, Nyraad at Vordingborg; on Lolland at 



