GRAMINEOUS CROPS. 113 



the larvae feed upon the juices of the host-plauts, and 

 weaken them to such an extent, that when the ears begin 

 to be formed, the straw is no longer strong enough to bear 

 their weight, but falls to the ground as though beaten 

 down by strong wind and rain. It must be borne in mind 

 that " the Hessian fly maggot does not feed in the ear, nor 

 does it feed along the outside of the upper part of the 

 stem." The ribbon-footed corn fly {Chlorops tceniopus) 

 feeds in the ears of corn, etc., and has been mistaken, by 

 some, for the Hessian fly. 



According to Dr. Lindeman (paper loc. cit.), the Hessian 

 fly lives about twenty-eight days in the larval stage, it 

 then changes to a brown pupa (Fig. 43 and D) some- 

 what resembling a small " flax-seed." Hence the reason 

 that the puparia are sometimes spoken of as "flax- 

 seeds." The period that the insect remains in the pupal 

 stage depends upon circumstances. On the authority of 

 Miss Ormerod, " it may occur, under natural and favour- 

 able circumstances, so soon that the whole time occupied 

 in the life of the fly from egg to development is only about 

 forty-eight days"; or, it may hibernate in the pupal 

 stage until May or even later in the following year. The 

 perfect insect (Kg. 43 A) is about five-sixteenths of an 

 inch across the expanded wings and with a body-length 

 of two lines (^th in.). The head of the male is black, 

 with long brown antennae and small pink proboscis. The 

 thorax is black with two lines of white hairs running 

 along the dorsal side, and also a few similar hairs on each 

 side of the thorax. The abdomen of the male is black, 

 except at the posterior end, where it is of a pinkish 

 colour. The posterior end of the abdomen " is provided 

 with a pair of claspers of a brown colour, between which 

 are seated the generative organs." The wings, which are 



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