24 



have attracted attention by its appearance in roses in the open 

 air, and its gradual occurrence farther and farther inland does 

 not imply an American origin. 



It affects the most seriously a species of rose that requires 

 a very warm, yet ventilated environment, and which, indeed, 

 is one of the most difficult varieties to grow successfully in this 

 country, besides being of European origin. In England and 

 Europe there is also a rose-attacking insect which can only be 

 separated anatomically from our species by the number of an- 

 tennal joints, a character known to be somewhat variable. 

 The habits of the two are very much alike, except that in Britain 

 the larvae affect the leaf buds and not the blossom buds, both 

 in the rose-houses and in the open air. Our species attacks 

 roses only in rose-houses, largely confining its ravages to the 

 blossom buds, but when attacking the leaf buds affects them as 

 does the English species. In Britain, and in the open air, the 

 wild, or dogrose, though it grows rapidly, can not certainly 

 make as rapid growth as does the Meteor in our rose-houses, 

 where all the ingenuity of the grower is centered on producing 

 the most rapid and vigorous growth possible. It is doubtful if 

 the American species could, under these conditions, develop in 

 any considerable numbers in the leaf buds, as the growth of the 

 buds is so accelerated by artificial conditions that there is not 

 time for the larvae to develop within them before they become 

 too much expanded and too tough to aduiit of the larvae affect- 

 ing them. The blossom bud, being of a slower development, 

 affords a longer time for the larvae to mature, and, besides, pre- 

 sents food of a different character from that of a leaf bud. 



To sum up the whole discussion, then, it is not now possible 

 to regard our American species as the same as that occurring in 

 England and Europe, known as Dichelomyia rosarum Hardy, 

 but that it is closely allied to that species can not be doubted. 

 We must wait for future studies to show us whether our Amer- 

 icanized form has sufficiently developed to admit of its being 

 separated as a new genus and species. 



I have held to Mr. Coquillett's specific name because it is 



