Leucozona. 241 



keel-shaped, the lower part somewhat protruding and with a pro- 

 truding central knob; the sides of epistoma somewhat descending. As 

 the lower part of epistoma is protruding and the drooping lateral 

 angles of the mouth edge only slightly retreating, the sides of epistoma 

 are rather broad below, and they have here a slight, oblique keel. 

 (Mik, Wien. ent. Zeitg. XVI, 1897, 63, expresses this in the foUowing 

 terms: "Die Backen sind nåmlich gut so breit wie der halbe verticale 

 Durchmesser des Auges"); it is in reality the sides of epistoma which 

 are broad, the jowls themselves are slightly descending. Epistoma is 

 yellow but with a black middle line and also the lower side parts 

 black; it is hairy on the sides. The mouth parts chiefly resemble 

 those in Syrphus; proboscis rather long; labrum of the iisual shape 

 and likewise maxillæ; the palpi long, club-shaped and more or less 

 recurved at the end. Thorax about quadrate; scutellum yellow, it 

 has as fringe below the margin. There are no bristles present. Ab- 

 domen somewhat short, broadest behind the middle about the hind 

 part of third segment; it is blackish with a broad, pale basal band 

 or pair of spots; it has in the male the same number of not trans- 

 formed segments as in Syrphus, viz. five, both on the dorsal and ven- 

 tral side; the first is very small and likewise the fifth; but generally 

 the fifth dorsal segment is turned a little to the right and the fifth 

 ventral hidden, the normal shape of the segment therefore only seen, 

 when the abdomen is stretched well out. Genitalia small. In the 

 female there are five visible segments, the rest more or less hidden. 

 Legs simple. Wings of usual shape, with a blackish band or blotch 

 about the middle; medial cross-vein before the middle of the discai 

 cell; vena spuria distinct. Squamulæ as in Syrphus, but blackish, the 

 hairs on alar squamula considerably flattened. Pliimula with longish, 

 plumose hairs. 



The genus w^as separated from Syrphus by Schiner in 1860, chiefly 

 by the peculiar abdominal markings; Mik adds in 1897 (1. c.) as 

 characters the wing band and the shape of the face; these are in 

 reality the distinguishing characters, and I think the genus may be 

 kept on them. 



As far as I am aware the developmental stages are not known. 



The species occurs on various flowers on meadows and in fens; 

 Schiner states that it occurs especially in the mountains. 



Of the genus only one species is known, also occurring in Denmark. 



1. L. lucorum L. 



1758. Linn. Syst. Nat. X, 592 et 1761. Fn. Suec. 1803 et 1767. Syst. 

 Nat. XII, 2, 985, 36 {Musca). — 1775. Fabr. Syst. Entom. 766, 19 (Syrphus) 



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