Syrphus. 



311 



Fernale. Vertex broad, black and shining, the black space near]y 

 quadrate, from it goes a black middle line forwards which soon widens 

 and forms a large, black Imiule above the antennæ; side dust spots 

 large ; the hairs black. Abdominal lunules distinctly narrower than in 

 the male. Legs as in the male, tårsi, especially the front ones, rather 

 obviously flattened. 



Length about 10 — 11,5 mm. 



S. lapponicus is very rare i Denmark, we have only one specimen, 

 a male, taken by Stæger in Ordrup on ^^'li 1843, no doubt just the 

 specimen mentioned by Zetterstedt (1. c. VIII, 3131). 



Geographical distribution: — By the confusion^of the species in 

 question it is not possible to give the distribution with certainty, but 

 the species occurs in Scandinavia, towards the north to northern 

 Sweden, in Finland and in England, and it is recorded from all 

 Europe ; it is also recorded from North America but the determination 

 is not certain. 



20. S. arcuatus Fall. 



1817. Fall. Dipt. Suec. Syrph. 42, 1 1 {Scaeva). — 1822. Meig. Sysl. Beschr. 

 III, 302, 43. — 1843. Zett. Dipt. Scand. II, 719, 22 (Scaeva). — 1862. 

 Schin. F. A. I, 305, p. p. — 1907. Kat. palåarkt. Dipt. III, 58. 



Male. Frons broad and somewhat inflated, almost as in Lasioph- 

 thicus, the upper angle obtuse ; epistoma likewise broad, yellow, central 

 knob blackish or brown and mouth edge 

 more or less so. Jowls æneous. Vertex 

 and frons black-haired, the latter densely 

 but the w^hole front half bare; epistoma 

 yellow-haired, above at the sides of the 

 antennæ are black hairs. Occiput grey 

 pruinose, the hairs white below, yellowish 

 upwards; just above some black, over- 

 hanging hairs. Eyes bare; there is a space 

 of large facets about as in Lasiophthicus 

 but a little less pronounced. Antennæ 

 brownish or blackish brown, pale belov^, 

 third joint oval, longer than the two basal 

 joints together; arista as long as or longer than the antennæ. Thorax 

 blue, brightly shining. a little yellowish at the sides, especially on the 

 postalar calli; it is clothed with yellow hairs, somewhat dense at the 

 sides. Scutellum dark yellow, somewhat bluish, black-haired, at the 

 basal corners and the margin are yellow hairs. Pleura with long, 

 yellowish hairs. Abdomen marginale, duU black, shining at the apex 



Fig. 125. 

 Head of S. arcuatus d". 



