INJURIOUS INSECTS. 265 



INSECTS INJURIOUS TO VEGETATION— No. 2. 



(NSECTS OF THE GENUS CECIDOMYIA, INCLUDING THE HESSIAN AND 



WHEAT-FLY^ 



«Y ASA FITCH, M. B^ 



It is the tleslgn of the articles, of which the present forms the 

 t^ommencement, to lay before the reader as full and accurate an ac- 

 count as the writer's investigations and means of information will 

 enable him to do, of a genus of insects, which, in consequence of 

 the ravages which some of its species annually commit, justly ranks 

 first in importance in the consideration of the tillers of our soil, 

 This design consequently embraces a precise statement of the differ- 

 ent marks which characterize each species in the several stages of 

 Its existence ; its habits and instincts; the depredations which it 

 commits upon the particular kind of vegetable which it inhabits ; 

 the most approved measures for lessening or preventing its depre- 

 dations, together with a description of the natural enemies of each 

 species, which aid in keeping it from becoming excessively multi- 

 plied. In the course of these communications, it is hoped, that 

 some contributions may be made of interest and value, both to the 

 .ause of agriculture and of science. 



-INSECTS ALLIED TO THE CECIDOMYliB. 



Preliminary to entering upon a consideration of the particular 

 species of this genus, it is important that we ascertain with preci- 

 sion what characters belong to the group of insects with which 

 this IS classed, and what aTe the marks by which an insect pertain- 

 ing to this genus may be clearly distinguished from its closely 

 •alhed associates. Though nothing original will be embraced under 

 this head, it is presumed that what it contains will still be valuable 

 to those persons residing in rural districts, and therefore most fa- 

 vorably situated for making observations, but who at the same time 

 have access to no large public library, containing those works on 

 natural history from which full information respecting the natural 

 alliances of these insects may be obtained. Any one not well 

 acquainted with, or overlooking these .generic and family marks^ 



