210 DISEASES OF THE ROSE. 



is plenty of air, free access of sunshine to them, absence of moisture; and, if 

 possible, the entire removal of overhanging trees, walls, etc. The influence of 

 these atmospherical agents hardens the texture of the shrubs, and thus renders 

 them impenetrable to these insects. In addition to this, their indolence and 

 tenderness makes them prefer the shade for laying eggs, which seems never to be 

 done but in darkness. 



On terminating this little work, I propose to leave the solution of several points 

 to those who shall continue it : 



1st. What is precisely the species of the saw-fly, whose larva commits the 

 havoc I have described 1 



2d. Is that the true white-footed saw-fly, which I have designated by that name. 



3d. What transformation does this larva undergo, after it leaves the passage 

 which it has dug 7 



4th. Does it belong to the species of the Selandria Excavator 7 



5th. Where does it await the period of its transformation into a perfect insect *? 



We have enumerated but a very small part of the numerous 

 insects which infest the rose, and in the absence of correct infor- 

 mation on this important branch of floriculture, it is much to be 

 hoped that farther investigations will be made by men of leisure. 

 As an instance of the great variety of these insects, a French 

 writer remarks, that " he found in less than an hour, on the leaves 

 of two species only of the Rose, six kinds of small caterpillars, all 

 differing from each other in the number of their feet, the color of 

 their head and body, and the lines and points with which they were 

 marked. Their habits were all apparently the same. They 

 lived between two or three folds, which they had secured in 

 shape by the films of their silk. Thus enveloped and pro- 

 tected, they eat the leaf until it is wholly or at least partly con- 

 sumed. They then endeavor to establish themselves on another 

 leaf, in which also they enwrap themselves and consume it in 

 the same manner. The plants attacked by these caterpillars are 

 known by their ruffled leaves, partly eaten and more or less cov- 

 ered with silk." The writer does not give their name, nor the 

 result of any experiments for their destruction ; he merely men- 

 tions it, as an instance of the great abundance of insects on almost 

 every plant. Such being the case, there is abundant room for 

 farther observation and research. 



