386 Syrphidae. 



short-haired, only the anterior feniora with longer hairs on the postero- 

 ventral side; hind femora setulose below; hind tibiæ as usuai shghtly 

 incurved on the posterior side near apex; hind metatarsi a little 

 thickened. Glaws and pulvilli well developed; empodium spine-shaped, 

 hairy. Wings somewhat long, considerably longer than abdomen; 

 medial cross-vein well before the middle of the discai cell; upper 

 marginal cross-vein somewhat angular, sometimes with small veinlets 

 from the angles; discai vein curved somewhat strongly down at the 

 apex of the discai cell; radial vein with fine bristles on the basal part;^ 

 vena spuriå distinct, in its last part quite parallel with the discai vein, 

 and thus also curved at the end. Alula large. Scuamulæ not narrow^ 

 alar squamula with short, simple hairs, thoracai squamula with long, 

 branched hairs. Plumula developed but not long, with simple and 

 some slightly branched hairs. 



The developmental stages are relatively well known. Zetterstedt 

 mentions pupæ of B. (Hammerschmidtia) ferruginea (Dipt. Scand. II, 

 687) ; they were found on a dry tree trunk on ^"'k ; further (ibid. 688) 

 the pupa of H. vittata found in summer. According to Brauer Scholtz 

 has mentioned the larva of H. conica from exsuding sap on trees 

 (Zeitschr. f. Entom. Breslau 1848 — 49). The developmental stages of 

 B. hicolor are mentioned by v. Roser (Wiirttemb. Gorr. Blått. 1834, 10) 

 from exsuding sap on Aesculus; they are noted by Leon Dufour 

 (Bull. Soc. Ent. de Fr. 2, IV, 1846, XL VII) and fully described by the 

 same author (Ann. d. Se. nat. IX, 1848, 199, PI. 16, fig. 1—5); the young 

 larvæ were found in April in exsuding sap on stems of Ulmus, in 

 October they were fuU grown and they pupated in January and 

 developed in April. I have myself examined the developmental stages 

 oi B. hicolor; the larvæ were taken in exsuding sap on stems in April 

 and under the bark on a stub of a beech on ^k, developing on -U^ 

 and larvæ and pupæ were found at the foot of a Populus attacked 

 by CossMS-larvæ on ^^/s, they developed in April; finally larvæ were 

 taken in holes of Cossus in a Poplar in August, but I do not know 

 at what time they developed. 



The larva of B. hicolor is flattened below, somewhat arched above ; 

 it is rounded in front, a little more tapering behind and nearly parallel- 

 sided. Above the mouth is a process with two small, two-jointed 

 papillæ, the antenna-like papillæ; there are no mouth hooks. At the 

 hind margin of the prothoracal segment lie the anterior spiracles at 

 each side as very small chitinous tubercles. There are twelve segments 

 in all, but head and prothoracal segment retracted. The body is 

 corrugated and the dermis chagreened; each body-segment shows two 

 corrugations, separated by a furrow but united towards the sides ; the 



