234 THE APPLE CULTUR18T. 



they acquire their full size, when they appear like Fig. 86. 

 After the Canker-worm has attained its full size, it either 

 crawls down the tree or lets itself down by means of a silk- 

 en thread, and burrows in the ground, where, at a depth of 

 two or three inches, it forms a rude cocoon. of particles of 

 earth intermixed with hair. Within two days after com- 

 pleting the cocoon, the worm becomes a chrysalis of a light- 

 brown color. The sexes are now distinguishable, the male 

 miller, shown at Fig. 87, being slender; while that of the 

 female is much larger, and destitute of wing-sheaths (Fig. 

 88). In the 'New England States, the worms descend into 

 the ground during the last of June, where most of them 

 remain till early the following spring, though many of them 

 change to moths and issue during the mild days of early 

 winter. 



Manner of Extermination. The sole object of the female 

 moth of the Canker-worm, after she leaves the earth, seems 

 to be to provide for the continuance of her kind ; and she 

 instinctively places the precious burden, which is to give 

 birth to the young which she herself is destined never to 

 behold, upon the tree whose leaves are to nourish those 

 young. 'All her life-energy is centred in the accomplish- 

 ment of this one object; and she immediately makes for 

 the tree upon issuing from the ground. Consequently, 

 any thing that will prevent her ascending the trunk will, in 

 a great measure, preserve the tree from the ravages of the 

 worm. Numerous, indeed, have been the devices to accom- 

 plish this desired object. Tar, applied to strips of old can- 

 vas, sheep-skin, or stiff paper ; refuse sorghum-molasses, or 

 printers' ink, applied in a similar manner ; tin, lead, and rub- 

 ber troughs to contain oil, tin-plate collars sloping down- 

 ward, belts of cotton-wool, etc., have all been used with 

 satisfactory results, in most instances, according as they 

 have been used intelligently or otherwise. All these ap- 



