236 Syrphidae. 



reddish dorsal and lateral lines; towards the time for the emerging 

 the paler, more transparent pupæ show the imago with its markings, 

 curiousl)' shortened in the nearly round case; he adds that the pupa 

 illustrates more strongly than usual how the dried larval skin, when 

 forming the puparium, expands greatly at the narrow cephalic end, 

 and shrivels to a mere scrap at the wide anal end, and this is in 

 accordance with my above description, 



According to the observations the larva feeds on Tortricid larvæ; 

 Ghapman placed larvæ in a box with larvæ of Hastula hyerana, and 

 he saw them attack and suck the larvæ and no doubt it was their 

 natural food. When full grown they pupated and the imagines came 

 at the end of April and the beginning of May. As they emerged so early 

 he naturally concludes, that there must be a second brood and this 

 must feed on some other prey, perhaps Aphides; on Sicily he also 

 found the larvæ in spring, and the imagines emerged from ^'^U and 

 further on, but at Lautaret he found the larvæ on ^/s and they were 

 bred some weeks later; Silvestri found his larvæ in spring. With us 

 and in other northern climates the species is exclusively autumnal as 

 imago, my dates of capture are ^^li — ^-'/o and the first date is more 

 early than is commonly the case, and as noted above my pupæ 

 developed at the end of August and on ^-'ho; I therefore think we 

 have only one brood, and probably the larva hibernates in a younger 

 or older stage, and also when more than one brood occurs it is pro- 

 bably the larva that hibernates. The larva is very voracious, Silvestri 

 thinks that one larva may during its life-time devour no less than 

 100 larvæ of Prays oleellus. The food of this larva seems thus to 

 be Tortricid larvæ ; Ghapman suggests however, as remarked, that they 

 may perhaps at certain times in the season feed on Aphides, and 

 one of the pupæ I mentioned above was taken as larva between 

 Aphides. 



Of the genus two palæarctic species are known, our X. comtus 

 and X. parhyalinatus Big. which latter is only known from Madeira. 



1. X. comtus Harr. 



1776. Harr. Expos. engl. Ins. 105, PI. XXXII, fig. 47 (Musca). — 1901. 

 Verr. Brit. Fl. VIII, 317, 1, figs. 266 — 267. — 1907. Kat. palåarkt. Dipt. III, 

 51. — Scaeva hyalinata Fall. 1817. Dipt. Suec, Syrph. 43, 13. — Syrphus 

 hyalinatus 1822. Meig. Sysl. Beschr. 111,312,56. — Scaeva hyalinata 1843. 

 Zett. Dipt. Scand. 11, 722, 25. — Melanostoma hyalinata 1862. Schin. F. A. 

 I, 290. 



Male. Frons and epistoma black or bluish black, yellowish pruinose 

 except on a space above the antennæ and the central knob. Vertex 



I 



