THE CANADIAN ENTOMOLOGIST. 205 



and in 1879 in Rusland. I find no statements of injury done by the fly 

 in Germany after i860, and the reports for Bohemia for 1872 and 1879 

 state directly that the fly was not observed. Dr. Schiner, in Vienna, had 

 till 1864 seen no specimen ; the best proof that it had not been obnoxious 

 in Austria. 



Dr. Wagner was the first to acknowledge the identity of C. secalina 

 and the Hessian fly. In observing the manner of life and the time of 

 swarming of the fly in Hesse, and comparing both with the time of the 

 departure and the arrival- of the Hessian troops, Dr. Wagner comes to 

 the conclusion that the importation of the fly by those troops is strictly 

 impossible. 



If we consider the positive evidence of the existence of the Hessian fly 

 in Europe, we find that between 1830 and 1840 jt occurred in four 

 localities on the northern shore of the Mediterranean. It appeared in 1850 

 more to the north in southern Rusland, and advanced strictly westward 

 through Germany till i860 as a very obnoxious pest. After all I think 

 it would be hardly more difficult to accept and to prove that the fly was 

 introduced by the energetic trade with the Mediterranean from America, 

 and became obnoxious only after acclimatisation, as to accept the intro- 

 duction into America from Europe. It is difficult to suppose that the 

 fly had been overlooked by such a number of prominent Entomologists 

 as those named. Dr. Wagner accepts as a fact that the fly was imported 

 from Asia to Europe and from Europe to America. The same supposi- 

 tion was made long ago by T. W. Harris, because the fly is connected 

 with the cereal grasses, and therefore their original home was presumed to 

 be the same with those plants. Against this conclusion I have to make 

 two objections. First, the fatherland of these plants is unknown. That 

 they live still wild in Persia, as Dr. Wagner supposes, is not proved at all. 

 Buffon also remarks that our cereals are not known to grow wild 

 anywhere, and later statements have always been proved to be unfounded- 

 The fly is not found till now in the Orient. Second, /'/ is not true 

 that such an obnoxious insect is strictly limited to some few species of 

 plants. The potato bug has given abundant evidence that an insect 

 not obnoxious before may become so by finding a related plant better 

 suited to its taste. Dr. A. Fitch (Rep. II., p. 297) well says, in speaking 

 of some wheat and barley flies, "As these flies appear to be native species, 

 it is probable that before wheat was cultivated upon this continent they 

 sustained themselves upon some of our wild grasses. Their numbers 



