202 THE CANADIAN ENTOMOLOGIST. 



III. The fly was not known to exist in Germany before 1857. 

 The fly must have existed in Europe and in Germany before it could 

 have been imported with the troops. Dr. Fitch tries to settle this most 

 important question by the following statements : 



Mr. Duhamel, in Monceau (I have compared the original), says that 

 '• a number of white worms have been found on the wheat near Geneva, 

 in 1755, which after a time turn to a chestnut color ; they place themselves 

 betwixt the leaves and gnaw the stalk; they are commonly found betwixt 

 the first joint and the root ; these animals appeared about the middle of 

 May." 



It is rather strange that just this passage has been quoted and always 

 reprinted. Mr. Duhamel says plainly, " the Jarva gnaws the stalk." Now 

 Dr. A. Fitch says (p. $$), "the larva of the Hessian fly lives upon the 

 sap; it does not gnaw the stalk." And Dr. Packard says (p. 15), "their 

 soft and fleshy undeveloped mouth parts do not enable them to gnaw the 

 surface of the plant." 



The fact that the stalk was gnawed shows evidently that the insect was 

 not the Hessian fly, but a species of Oscinis ; the larvae of some species of 

 which would gnaw the stalk — or perhaps Opomyza florum. The pupa 

 of those species is also brown and appears above the root between the 

 leaves and the stalk, and the imago appears just as Duhamel states, in 

 the middle of May, one month later than the Hessian fly. Prof. J. Kuehne 

 remarks that the effects produced upon the plants by Opomyza are similar 

 to those of the Hessian fly. 



Therefore the quotation of Duhamel is entirely out of place, and 

 this is, by the way, the only one by which the existence of the fly in Europe 

 before the war has been corroborated. I have gone through the literature 

 from 1770 to 1804, without finding any statement of similar devastations 

 of wheat, for Germany, for France and for Spain. There exist a number 

 of books where such a calamity in France would have been noted if it 

 had existed. 



I have not been able to consult the long and detailed report of Sir 

 Joseph Banks to the British Government. An extract given by Kirbyand 

 Spence shows that the fly did not exist in England in 1788, and that 

 no where on the continent its existence or similar devastations were known. 

 In 1834, Prof. Kollar, of Vienna, in his treatise on injurious insects, 

 published an account on some devastations done by the Hessian fly — he 

 has first in Europe used this name for a European species — in Altenburg, 



