558 



Sj'rphidae. 



the discai cell; the basal part of the radial vein with distinct, fine 

 bristles. No stigmatical cross-vein or an indistinct one. Thoracai 

 sqiiamula with long, richly branched hairs ; the hairs have long stems 

 which bear many small branches; alar squamula with short, slightly 

 flattened hairs, longer in bomhiformis than in mussitans. Plumula not 

 short, with simple hairs or these branched only just at the base. 



As far as I am aware the developmental stages are not known. 



The species of Arctophila, which genus Schiner separated from 

 Sericomyia in 1860, are large, beautiful Bomhiis-Wke flies. They occur 

 in and at woods and also on fieids, and they frequent various flowers. 



Of the genus 3 palæarctic species are known, 2 occur in Denmark. 



Tahle of Species. 



1 . The dense pile black and yellow or pale 1 . bombiformis. 



— The dense pile all yellow i2. mussitans. 



1. A. bombiformis Fall. 



1810. Fall. Specim. Entom. 25 et 1816. Dipt. Suec. Syrph. 16, 1 (Syr- 

 phus). — 1822. Meig. Syst. Beschr. 111, 343, 1 Tab. XXX, Fig. 8 (Sericomyia). 



— 1843. Zelt. Dipt. Scand. II, 644, 1 (Sericomyia). ~ 1862. Schin. F. A. 1, 

 331. — 1907. Kat. palåarkt. Dipt. III, 140. 



Male. Vertex black, somewhat yellowish pruinose ; frons brownish 

 yellow pruinose, with an impressed middle stripe; epistoma strongly 



descending, the descending part nearly as long 

 as the height of the eye; there is a small 

 central knob ; epistoma is brown, whitish or 

 yellowish white pruinose, the pruinosity leaving 

 the middle stripe bare, but the stripe not 

 reaching to the antennæ; the lower lateral 

 parts from the eye downwards bare and black; 

 vertex with black or brown, posteriorly with 

 some yellow hairs ; frons with long yellow and 

 some black hairs; epistoma with erect, pale 

 hairs but only on the sides near the eye- 

 margins, for the rest bare; the hairs are short 

 below and here present only as a row along 

 the eye. Occiput greyish yellow pruinose ; the 

 hairs brownish black below, yellow above and 

 here also some black hairs; at the upper 

 corners of the eyes the black hairs are quite short and bristly. 

 Antennæ red, third joint more or less darkened ; arista reddish brown, 

 long plumose, the rays blackish. Thorax dull black, greyish pruinose 



Fig. 186. Head of 

 A. bombiformis S. 



