DISEASES AND INSECTS ATTACKING THE KOSE. 145 



creatures eat the upper surface of the leaf in large irreg- 

 ular patches, leaving the veins and the skin beneath un- 

 touched ; and they are sometimes so 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 

 afterward. 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 yellowish hue. They then 

 leave the rose-bushes, some of them slowly creeping down 

 the stem, and others rolling up and dropping off, espe- 

 cially when the bushes are shaken by the w^ind. 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 appointed 

 work of destruction in the autumn ; they then go into the 

 ground, make their earthy cells, remain therein through- 

 out the winter, and appear in the winged form, in the fol- 

 lowing 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 w^hom a premium of one hundred dollars for the most 

 successful mode of destroying these insects was oflered in 

 the summer of 1840. About ten years ago, I observed 

 thein in gardens in Cambridge, and then made myself ac- 

 qainted with their transformations. At that time they 

 had not reached Milton, my former place of residence, 

 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 pup 



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