52 AN ACCOUNT OF BRITISH FLIES. 
Mimosciara, Rd. 
Yposatea, Rd. 
Ocelli wanting. Wings pubescent. Antennz moniliform in ¢, 
sub-moniliform in 9, 16 joints. First longitudinal being short, third 
forked (Fig. 74). 
Colpodia, Wtz. One species is reputed as British. The second 
longitudinal vein forms a curve before the cross-vein, and joins the 
margin beyond the tip of the wing (Fig. 8a). 
Cecidogna, Lw., antennz 11-jointed ;* Micromyia, Rd., is another 
genus found in Britain, and given in Bergenstamm and Léw’s work. 
Zygoneura, which shows certain affinities to the Cecidomyide men- 
tioned before, and also to Scara, one of the JZycetophilide, is now 
included in the latter family ; but is no doubt a transitional form 
between the two. Azarefe is now placed in the Bibionide. 
The following are the genera and sub-genera found in England, 
the names being those used by Verrall and in Bergenstamm and 
Low’s classification} : Zasioptera, Mg.; Cecidomyia, Mg.; Asphon- 
dylia, Lw.; Diplosis, Lw.; Hormomyia, Lw.; Dirrhiza, Lw.; Epi- 
dosts, Lw.; Winnetsia, Rd.; Campylomyza, Mg.; Micromyia, Rd. ; 
Catocha, Hal.; Lestremia, Mcq.t Most of these are considered 
sub-genera of Cecidomyia by Loew ; by others as true genera. By 
tar the most important is Cecidomyia proper, which contains as many 
as fifty species indigenous to Britain,§ and amongst these by far the 
most interesting and important is the Hessian-fly (C. destructor), 
which we now proceed to describe, with other species of this sub- 
genus. 
Lestremia, Macq. = 
: Bote _ {Dasyneura, Rd. 
SuB-GENus.— Cecidomyia, Lw. = | rhabdophaga, Westw. 
Cecidomyia destructor, Say (the Hessian-Fly). 
The egg of the Hessian-fly, which is small and cylindrical, is 
described by some as being rounded at each end, by others as being 
pointed at each end,|| pale-orange colour at first, with reddish dots, 
becoming darker later and transparent the third day ; about ‘oz mm. 
long by ‘oo8 broad. The larvae emerge on the fourth day. Accord- 
ing to Mr. Enock,‘! a female will lay from roo to 150 eggs; others. 
say as many as 280. They are laid on many separate plants of 
* This is now merged into the sub-genus Zestremia. Diomyza, Clinoryncha, 
Heteropeza and Tritozyga are other foreign genera. 
+ Synopsis Cecidomyidarium, 1876, J. E. von Bergenstamm and Paul Low. 
t The following is a reputed British genus: Colfodza. 
§ Ninety or more, if we include reputed and doubtful records. 
el ony Report of Department of Agriculture, U.S.A.,” p. 208, 
1880-82. 
‘] Trans, Ent. Soc. of London, June, 1891. 
