Brachyopa. 389 



behind, somewhat shining, and it is clothed with short, pale hairs, a 

 little longer at the sides and longest at the basal corners; on the 

 middle of the disc are short, black hairs and also on the "hinder half 

 of the side margin of second segment the hairs may be black. Venter 

 yellow with short, pale hairs. Legs yellow or reddish yellow, anterior 

 tarsi with the last joints blackish, front metatarsus also somewhat 

 darkened above, hind tarsi dark, The legs short-haired, anterior 

 femora with longer hairs on the postero-ventral side ; the longer hairs 

 are yellow, at the apex of the femora often some black; the short 

 hairs on the hind femora mainly black on the anterior side; on the 

 tibiæ the hairs are more or less black, especially above, but the hairs 

 upon the whole varying in colour; hind femora densely black setulose 

 below, the short bristles forming two rows towards the apex, leaving 

 a bare space in the middle, and traces of the same may be more or 

 less visible below the apex of the middle femora. Wings a little 

 yellowish tinged, especially towards the anterior margin; the upper 

 marginal cross-vein with a small angle in its lower third and some- 

 times here with a small veinlet inwards; the lower angle with or with- 

 out a veinlet; the radial vein with fine bristles on its basal part. 

 Squamulæ and fringes whitish yellow. Halteres pale yellow. 



Female. Vertex and frons broad, dull grey, with short, pale and 

 black hairs; the space above the antennæ red, shining and bare; the 

 lower part of epistoma a little more protruding and descending than 

 in the male, and epistoma pruinose only below the antennæ, the rest 

 bare and shining. Hind femora setulose only below the apex, for the 

 rest with fine, pale hairs. 



Length 6 — 8,5 mm. 



The larva and pupa are described above. 



This species varies somewhat in size, in the presence of bristly 

 hairs and in the colour of the hairiness. Verrall suggests the existence 

 of a closely allied, undescribed species with the humeri scarcely red- 

 dish and no black hairs at the sides of the second abdominal segment; 

 according to my experiences I should consider such specimens to be 

 only varieties. 



B. hicolor is rare in Denmark ; Charlottenlund, Ordrup Krat, Ryget 

 Skov at Farum Sø, Holte, Geel Skov, Hillerød, Boserup at Roskilde 

 and Tisvilde; it is a spring species, my dates are ^'^/s— ^/b. It occurs 

 in woods and thickets on trunks and stems of trees with exsuding 

 sap and often on trees attacked by Cossus, but also on others, as also 

 flying in low herbage; the females are very rare and only taken on 

 trees. The larva was taken in sap in Charlottenlund in April (Schlick), 

 in Geel Skov under the bark on a trunk of a beech on "'/s, it developed 



