272 Syrphidae. 



found at very different times, nearly through the whole year, as well 

 as newly emerged specimens may be found from very early to quite 

 late in the season; these species have, I think, several broods without 

 any regularity, just as many as the length of the warmer period will 

 allow, and they may hibernate in a younger or older larval stage, 

 according to the setting in of the cold period. Whether hibernation 

 may take place as egg or pupa I do not know, but I think it not 

 probable. In southern regions the number of broods in the year may 

 be greater, thus Martelli stat es that in Italy S. balteatus may be 

 assumed to have up to seven broods in the year. 1 have never ob- 

 served the eggs; according to Buckton (Mon, of Brit. Aphid. II, Roy. 

 Soc. 1879, 119) the egg-shell is ornamented with bifurcate papillæ; 

 the eggs are deposited singly and may often be seen on leaves of 

 oak, fir etc. where they are placed in the midst of Aphides. 



The species of Syrphus are beautiful and hvely flies; they occur 

 especially on localities with flowers, both in woods, in fens and on 

 commons and meadows; they are generally seen on flowers and 

 hovering around them, and tlie males of many or all species often 

 hover more or less high in the air in sunshine, especially on sunny 

 piaces in woods; they are generally exquisite hoverers; I once bred 

 a male of S. luniger in a bottle, not much wider than the distance 

 across the horizontally stretched wings, and the fly was able to hang 

 on the wings hovering on the same spot in the middle of the bottle 

 for a half or a whole minute. The genus goes far towards the north, 

 thus three species occur in Greenland, two of which are our lunulatus 

 and torvus. — Species of Syrphus may sometimes occur in vast 

 swarms; Verrall records (1. c. 339) two cases from Britain, both 

 occurred on ^^/s; the species were in one case S. rihesii (most 

 numerous), corollæ, luniger, Lasiophthicus pyrastri and one S. baltea- 

 tus-, they "appeared to have all hatched simultaneously, and to have 

 at once commenced buzzing about in the hot sunshine in a foolish 

 kind of way, without caring to take food, for most of them seemed 

 to be mere shells without any substance inside." Mr. Verrall once had 

 come upon the tail-end of a swarm, the individuals of which seemed 

 nearly all to be S. auricollis and its variety maculicornis. 



Of the genus about 65 species are known from the palæarctic 

 region; 33 have hitherto been found in Denmark. 



Table of Species. 



1 . Eyes distinctly hairy 2. 



— Eyes bare or almost so (in punctulatus and lasiophthalmus 



slightly hairy) 8. 



