340 Syrphidae. 



base, haired. Wings a little narrow; medial cross- vein well before 

 the middle of the discai cell; vena spuiia distinct, with a nodule 

 below the base of the cubital vein. Alula large. Squamulæ sonie- 

 what narrow, alar squamula with quite short, simple hairs, thoracai 

 squamula with not long, fine, branched hairs. Plumula very thin 

 and delicate, not densely haired, the hairs simple. 



This genus is well characterised by its long and narrow shape 

 and by the structure of abdomen, which in the male has the fifth 

 segment long with the hind margin not symmetricai, and in the female 

 at least seven visible segments; also the male genitalia are very 

 characteristic. Verrall gives as character that the abdomen in both 

 sexes has an unusual large number of segments and says that there 

 are flve in the male; but as seen this is not unusual, as most genera 

 show this number of not transformed segments, only the fifth segment 

 is here large, while in the other genera with five segments it is gener- 

 ally small ; in the female, on the contrary, the number of seven visible 

 segments is characteristic against the general number of five or six, 

 though this difference is no principal one, only caused by the apex 

 of abdomen being more protracted than usual, as the real total 

 number of segments is of course the same. Verrall states also under 

 his general description of the Syrphidae that the male genitalia of 

 Sphaerophoria are symmetricai; from the above it is seen, that this 

 is so far from being the case that on the contrary their unsymmetrical 

 shape even influences the fifth segment; only the large ninth segment 

 lies about symmetrically thus to some degree giving an impression 

 of a symmetricai shape of the genitalia. 



The developmental stages of several species are known. Rosel 

 (Ins. Belust. II, 1749. Muse. 31, Tab. VI) describes larvæ and pupæ 

 of S. scripta, found on piants among Aphides in April and May. The 

 stages of S. menthastri {taeniata) are described by Bouché (Naturg. d. 

 Ins. 1834, 51, Tab. V, Fig. 4 — 6); the larva was found among Aphides 

 on Gompositæ. Zetterstedt mentions (Dipt. Scand. II, 1843, 766) larvæ 

 and pupæ of iS. scripta, the larva was aphidiphagous, and (770) of 

 menthastri, the larva among Aphides on Vicia faba, the imagines 

 developed on ^/s — '^^/s. I have myself examined larva and pupa of 

 S. scripta and menthastri and the pupa of fiavicauda ; the larva of 

 scripta I took on a plant among Aphides on ^h, it pupated on 'Vt 

 and developed on 1^/7 ; Mr. Kryger took the pupa on grass on '^^Is, it 

 developed on =^^/8; the larvæ of menthastri I took on ^U in flood 

 refuse of reeds, they developed on -^^/s; Mr. Schlick took larvæ in the 

 same way, they developed in May; fmally Mr. Schlick took larva of 

 fiavicauda in flood refuse near the shore in late autumn, they developed 

 in the following spring. — The larva (of S. menthastri) is of the usual 



