^(50 Syrphidae. 



posterior spiracles lie close together, but not on any process; each 

 spiracle shows three slits; the anterior spiracles are small, placed 

 above the prothoracal segment on each side. The larva is green, with 

 a yellow or whitish yellow line along the dorsum, and a narrower 

 and sometimes less distinct line along each side. The length of the 

 fiill grovvn larva is about 15 mm or more. The pupa is elongated 

 ovate, broad and rounded in front, not much tapering behind; it has 

 the same spines or hairs as the larva; the posterior end is bend a 

 little downwards and above it are the posterior spiracles in the same 

 cavity as in the larva. The pupa is at first green, later on it becomes 

 more brown and more pellucid, and the enclosed fly is then disiinctly 

 seen through the puparium. The length of the pupa is about 9 mm. 

 The pupa rests attached with the posterior end to some leaf or stalk, 

 but MartelU (1. c. 40) records that at time for pupation the larva goes 

 down from the plant and goes 2 — 3 cm into the earth and pupates 

 here; I am inclined to think that here may be some error, as the 

 pupa is generally stated to sit on piants, and my larvæ pupated (in 

 captivity) on the leaves of Phragmites. The larva is aphidiphagous 

 and feeds, as seen from the above, on various species and it is very 

 voracious ; De Geer records that larvæ found among Aphides on Rosa 

 would not eat Aphides from Sambucus ; the same author saw a larva 

 which he had in captivity, attack a smaller one, as he had forgotten 

 to furnish them with Aphides. Martelli states (1. c.) that a larva may 

 eat during its life-time from 472 to 538 Aphides. Bloomfield mentions 

 (Ent. Month. Mag. XXXVI, 1900, 244) that pyrastri was bred from 

 pupæ of Plusia jota and gamma?; this, however, may be a mistake, 

 though the observation cannot be quite neglected, especially when 

 remembered that some Syrphid larvæ feed on Lepidopterous larvæ. 

 With regard to the hibernation I think the species hibernates as quite 

 young larva; the imagines are especially found in late summer and 

 autumn, and as recorded I bred pyrastri in the later part of August ; 

 certainly the imago does not hibernate, and then I think it most pro- 

 bable that it is the young larva. With us the species has only one 

 brood in the year, but Zeller records that farther towards the south 

 there are two, and Martelli states that in Italy are up to seven broods 

 in the year. According to Martelli the eggs are elliptic, 1,13 — 1,26 mm 

 long, of milk-white colour, with the shell ornamented ; they are depo- 

 sited singly on leaves with Aphides; the same author gives (1. c.) in- 

 teresting notes about the copulation and tells that the female flies 

 with the male on the dorsum to a secured place; he gives the dura- 

 tion of the copulation as about three hours. 



The species of Lasiophthicns occur on meadows and in woods. 



