330 BHECK'S BOOK OF FLOWERS. 



thick that not a leaf on the bushes is spared by them, and the 

 whole foliage looks as if it had been scorched by fire, and drops 

 off soon afterwards. They cast their skins several times, leav- 

 ing them extended and fastened on the leaves ; after the last 

 moulting, they lose their semi-transparent and greenish color, 

 and acquire an opaque yellowish hue. They then leave the 

 rose-bushes, some of them slowly creeping down the stem, and 

 others rolling up and dropping 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 excited the attention of 

 the Massachusetts Horticultural Society, by whom a premium 

 cf SI 00, for the most successful mode of destroying these in- 

 sects, was offered, in the summer of 1840. About ten years 

 ago I observed them in gardens at Cambridge, and then 

 made myself acquainted with their transformations. At that 

 time they had not reached Milton, my former place of resi- 

 dence, and have appeared in that place only within two or 

 three years. 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 or syringing the bushes with a liquor, 

 made by mixing with water the juice expressed from tobacco 

 by tobacconists, has been recommended ; but some caution is 



