292 Syrphidae. 



antero-dorsal side of hind tibiæ black, but on the anterior side all or 

 almost all yellow. Wings more hyaline Ihan in rihesii. 



Feniale. Frons as in ribesii. Abdominal bands generally a little 

 narrower than in the male. Legs chiefly as in the male and haired 

 in the same way, thus the hind femora are not yellow as in the 

 female of rihesii but with the basal three fourths black. 



Length 7,6 — 11,5 nmi. 



The larva and pupa are quite similar to those of S. ribesii. 



S. vitripen?iis is as common as ribesii and occurs in quite the 

 same way, but it is much more common in gardens. My dates are 

 ^<'/5 — ^/9. 1 have taken the larva in gardens among Aphides on Pyrus 

 and Prunus on ^/e, ^^le, the latter developing on ^^/e, and on ^^/e, 

 pupating ^"/e and developing ^,'7 — ^^/7, and I have taken a pupa on 

 the ground on ^^/v, it developed on ^^h. 



Geographical distribution: — All Europe, towards the north to 

 northern Sweden, and in Finland. 



Remarks: The three preceding species are very similar, even to 

 so high a degree that their specific value has been doubled, f. inst. 

 by Girschner (111. Wochenschr. f. Entom. 1897, 570). They are also 

 very nearly related as shown by the faet that they all have hairs on 

 the upper surface of the thoracai squamula, but after the examination 

 of great numbers of all three species I consent with Verrall in i'eeling 

 sure that the three species are quite distinct. S. torvus is distinguished 

 by the hairy eyes and darker antennæ; ribesii is in the male easily 

 distinguished from torvus by the practically bare eyes, and in the 

 female by the yellow femora ; vitripennis is in the male likewise 

 distinguished from torvus by the bare eyes; it is very similar to r/6es?7 

 but has the hind femora more black, the anterior tarsi paler and the 

 short hairs on the apical half of hind femora yellow ; in the female 

 it is distinguished from torvus besides by the bare eyes, by the anterior 

 femora being less and the hind femora more black, and by the paler 

 anterior tarsi; from ribesii it is distinguished by the not quite yellow 

 femora, and from both by the short hairs on the apical half of hind 

 femora being yellow. As seen the obviously haired eyes in the male 

 of torvus easily distinguish it, while this character is less obvious in 

 the female, and likewise the yellow femora at once distinguish the 

 feniale of ribesii; it is thus espccially the females of torvus and 

 vitripennis and the males of ribesii and vitripennis which are diffi- 

 cult lo distinguish, but they may be known with certainty by the 

 characlers given above. As to size torvus and ribesii are rather like, 

 but torvus is, however, the larger; vitripennis is upon the whole 

 smaller, but, as seen, large vitripennis may exceed even small torvus. 



