II FLIES WITH AQUATIC LARV^! 157 



described, 1 as living during its early stages in the 

 sap which flows from wounded elms. It creeps and 

 even swims about in this juice with great activity. 



The flies hatched from aquatic larvae have naked 

 wings, while those produced from tree-haunting larvae 

 have hairy wings. 



Some species of Ceratopogon sting, and inflict 

 painful wounds upon man. They are occasionally to 

 be found among other Tipulids upon the window- 

 pane, but their natural resort is the branches of trees 

 and shrubs. 



Like most aquatic Diptera, Ceratopogon passes the 

 winter in the larval form; the pupa and imago appear 

 in May or June, and young larvae abound in the 

 latter part of summer. The eggs are laid 100 or 

 more together in star-shaped clusters among the 

 confervse. 2 



DlXA. 



The larva of Dixa was first described by Reaumur 

 in a memoir published in 17 H- 3 It is, he says, only 

 seven or eight lines long. There are eleven segments 

 behind the head. The larva is almost always bent 

 double into the shape of a siphon, so that the head 

 and tail come close together. The bend is at the 



1 Laboulbene, Ann. Soc. Enlom. de France, 4 e Ser., Tom. IX. 

 (1869). 



2 Gercke, Verh. d. Vcr. f. natur-w. Unterhalt. Hamburg, 

 Bd. IV., p. 222-8 (1877). The larva and pupa have been well 

 figured and described by Meinert, De eucephale Myggelarver 

 (1886). 



3 Mem. de I' A cad. Roy ale de Paris. 



