36 CULTURE OF THE ROSE. 



as if it had been scorched by fire, and drops off soon afterwards. 

 They cast their skins several times, leaving them extended and 

 fastened on the leaves: after the last moulting, they lose their 

 semi-transparent and greenish color, and acquire an opaque yel- 

 lowish hue. They then leave the rose-bushes; some of them 

 slowly creeping down the stem, and others rolling up and drop- 

 ping off, especially when the bushes are shaken by the wind. 

 Having reached the ground, they burrow to the depth of an inch 

 or more in the earth, where each one makes for itself a small oval 

 cell of grains of earth, cemented with a little gummy silk. Having 

 finished their transformations, and turned to flies within their cells, 

 they come out of the ground early in August, and lay their eggs 

 for a second brood of young. These, in turn, perform their ap- 

 pointed work of destruction in the autumn : they then go into 

 the ground, make their earthen cells, remain therein throughout 

 the winter, and appear in the winged form in the following spring 

 and summer. During several years past, these pernicious vermin 

 have infested the rose-bushes in the vicinity of Boston, and have 

 proved so injurious to them as to have elicited the attention of 

 the Massachusetts Horticultural Society, by whom a premium of 

 one hundred dollars, for the most successful mode of destroying 

 these insects, was offered in the summer of 1840. In the year 

 1832, 1 first observed them in the gardens in Cambridge, and then 

 made myself acquainted with their transformations. At that time 

 they had not reached Milton, my former place of residence ; and 

 they did not appear- in that place till six or seven years later. 

 They now seem to be gradually extending in all directions ; and 

 an effectual method for preserving our roses from their attacks has 

 become very desirable to all persons who set any value on this 

 beautiful ornament of our gardens and shrubberies. Showering 



