36 Syrphidae. 



The species of Bassus are rather comnion as parasites on Syrphids, 

 this genus seems mainly to be dependent on Syrphids; the pupæ con- 

 taining Bassus are generally darker and a little smaller than normal 

 pupæ. 



Syrphidae earlier recorded from Detimark: — Kramer (Specini. 

 Insectol. Dan. 1760) has 5 Syrphids; Briinniche (Prodr. Insectol. Siæl- 

 land. 1761) has 10, and in Pontoppidan: Danske Atlas I, 1763, he 

 enumerates 14, all under Musca; these species are all common, but 

 otherwise nothing can be said about them; M. oestracea, which both 

 authors have, is no doubt E. intricarius. O. F. Muller (Faun. Fridrichsd., 

 1764) mentions 20 species of Musca which must be Syrphids, and in 

 1767 (Flor. Fridrichsd.) he mentions three more, in all 23 ; these are 

 likewise all common species and nothing certain can be said about 

 them, so that their presence in the synonymi is mostly due to con- 

 venience. His M. conopsoides, which is among them, is most likely a 

 Conops; M. oestracea is, I think, E. intracarius; of his two new species 

 M. fasciata and cyanea, the first is no doubt a Sphaerophoria (female), 

 and the other certainly FL albinianus F. ; this species should thus 

 alter its name, but I think this not advisable. Fabricius in his first 

 work (Syst. Entom. 1775) has four species from Denmark, all new, 

 viz. Syrphus elongatus [Baccha), podagricus [Neoascia), ruficornis 

 {Ferdinanded) and lugubris {Pipiza)\ these species are thus originally 

 described on Danish specimens; about Ferdinandea ruficornis see 

 under this species. In Spec. Ins. 1781 Fabricius has the same four 

 species, but in Mantis. Ins. 1787 he enumerates still three, Syrphus 

 rosarum and nectareus and Bhingia lineata, likew^ise all new ; of these 

 S. rosarum {Pyropjhaena) and R. lineata (Helophilus) are thus also 

 originally described from Denmark, while nectareus is a synonym to 

 balteatus De G. In Entom. Syst. IV, 1794 he moreover enumerates 

 S. subsultans and umbellatarum, both new, and of these umbellaiarum 

 is thus likewise originally founded on Danish specimens, while sub- 

 sultans is a Gymnopa. In his last work, Syst. Antl. 1805 Fabricius 

 has the earlier species, partly under new generic names, as podagricus 

 is now under Merodon, elongata under Baccha^ ruficornis, lugubris 

 and subsultans under Eristalis and the other species under Scaeva; 

 besides he describes here two new, Eristalis ater, which is a synonym 

 to Chilosia variabilis Panz. and Scaeva interrupta, a synonym to 

 Sphaerophoria menthastri L. (a female). Fabricius enumerates thus 

 in all 10 species of Syrphids from Denmark, and of these 7 are new 

 species. Zetterstedt has in Dipt. Scand. II, 1843, 102 species; in VIII, 

 1849 he has still 24 species, thus in all 126 species; but of these we 

 must strike out several; thus he has Volucella bombylans both as 



