398 Syrphidae. 



inanis, pellucens and homhylans are described; the work contains a 

 complete list of the eaiiier observations and of the literature; it is 

 here mentioned that the larva of V. homhylans hves in the nests of 

 B. lapidarius and muscorum, the larva of V. zonaria in nests of F. vul- 

 garis and crahro, and the larvæ of V. pellucens and inanis in nests of 

 V. vulgaris. Later on has Erné (Mittheil. schweiz. Ent. Ges. IV, 1876, 

 561) mentioned V. zonaria and inanis from nests oiVespa, and Nev^- 

 stead (Ent. Month. Mag. XXVII, 1891, 41) has observed larvæ of 

 V. homhylans in nests of F, germanica ; finally Verrall records (Brit. 

 Fl. VIII, 1901, 487, 491) that Sharp has bred V. inanis from nests of 

 F. crahro^ and he mentions V. pellucens from nests of F. vulgaris. I 

 have myself observed larvæ of F. homhylans and pellucens. The larva 

 of homhylans was found in the nest of B. subterraneus or an allied 

 species in September, and in the nest of an undetermined Bomhus on 

 ^''k ; the larva of pellucens was found fullgrown in nests of V. vulgaris 

 on ^li, further on ^/lo developing next spring, and on ^k in the earth 

 below a nest, pupating on ^2/4 and developing on ^^/s, and flnally in 

 the nest of an undetermined Vespa in September. VVe thus at present 

 know V. homhylans from B. lapidarius, muscorum, suhterraneus? and 

 perhaps from other species, and from V. germanica ; V. pellucens from 

 V. vidgaris; V. inanis from F. crahro and vidgaris and V. zonaria from 

 the same species of Vespa. No doubt the larvæ live only in such 

 nests as are found in or near the ground. 



The larvæ are of greyish or yellowish white colour, somewhat 

 flattened and especially rather flat above; they are a little attenuated 

 towards the head end; there are in all twelve segments; the head is 

 retractile, there are a pair of small, so-called antennæ, two-jointed 

 and ending with two small points, but there are no mouth hooks. 

 The dermis is finely chagreened and the body is strongly transversely 

 corrugated so that each segment shows three or four corrugations ; 

 above there are some small warts or wart-like spines on the corruga- 

 tions, and along the sides there are, according to the species, shorter 

 or longer spines, also surrounding the posterior end; all the spines 

 are spinulose; on the ventral side there are seven pairs of prolegs, 

 armed with hooks. At the hind margin of the prothoracal segment 

 lie the small anterior spiracles on each side, and above on the last 

 segment is a quite short or a little longer, brown spiracular process. — 

 The distinguishing characters of the larvæ of the different species are 

 the following. The larva of homhylans has on the two last thoracai 

 segments and the first abdominal segment about six spines on each 

 above in a transverse row and some at the sides; the six following 



