Syrphus. 291 



The larva is transversely corrugated, finely chagreened, with the 

 usual small, sofL brislles placed in Iransverse rovvs on some of the 

 corrugations and at the sides, and arranged in the usual way; the 

 posterior spiracular proeess brown, elliptical in transverse section and 

 a little cleft at the end, it is about 0,5 mm long. The larva is greyish 

 yellow with some translucent yeliow or reddish markings and a dark 

 middle line. The length is about 12 mm or more. The pupa is 

 elongated oval, broad and rounded in front, attenuated behind, some- 

 what flat below, arched above; it is very slightly chagreened and the 

 bristles very indistinct; in colour it is similar to the larva, generally 

 with a broad, serrated middle stripe. The length is 7 — 8 mm. 



<5. ribesii is very common in Denmark and occurs all over the 

 country, and like the preceding species on all localities and in great 

 numbers. My dates are '^^/4 — ^^/lo. The larva has been taken by Mr. 

 Schlick and myself in gardens and in woods among Aphides on Pyrus, 

 Rosa, Sambucus and Urtica, and it is known to occur on several 

 other planls; it has been taken on */?, developing on ^^/t, and on Vs, 

 pupating ^Vs and developing ^"^/s; I have also taken it among old 

 leaves on the ground on ^"/i, developing Vs, and on ^/a, developing 

 first in April. Pupæ have been taken on ^li and "^^h. 



Geographical distribution: — All Europe, tovvards the north to 

 northernmost Sweden, in Finland, and on Iceland; it occurs also in 

 North America. 



y. s. vitripennis Meig. 



1822. Meig. Sysl. Beschr. III, 308, 50. — 1843. Zett. Dipt. Scand. II, 

 708, 9 et 1849. VIII, 3132, 9 {Scaeva). — 1802. Schin. F. A. I, 310. — 

 1901. Verr. Brit. Fl. VIII, 370, 14. — 1907. Kat. palaarkt. Dipt. III, 72. — 

 Sijrphus topiarius Meig. 1822. Syst. Beschr. III, 305, 47 et 1838. VII, 131, 47. 

 — Scaeva confinis Zelt. 1838. Ins. Lapp. 602, 14. 



This species is very like the two preceding, but as a rule smaller. 

 Male. Frons with a black lunule and above it yellow, more or less 

 greyish pruinose. Jowls yellow. Eyes practically bare. Antennæ pale 

 as in ribesii. Thorax and abdomen as in ribesii. Legs about as in 

 ribesii^ anterior femora with less than the basal third black, but hind 

 femora more black as about the basal three fourths or more are 

 black; hind tibiæ yellow or with only faint traces of a darkening in 

 the middle; anterior tarsi paler, quite or almost quite yellow. The 

 long hairs on femora all yellow, and no black hairs above the apex 

 of middle femora; the .^ihort hairs on the apical half of hind femora 

 quite yellow, or only some few black intermingled ; the hairs on the 



19* 



