322 The Canker Worm; its Habits, and Remarks on 



driven out both by winds and rains, and thrown on the bark of 

 the trees to their great injury, at least unless better remedies 

 can be devised than I have seen put in practice. The gutters 

 also, as they are generally made, are quite too narrow, and if 

 the insects are in great force, are quickly choked up or bridg- 

 ed over. They should be at least two inches wide in the 

 clear, at the top, which would much increase the expense. 

 Besides, they must be fitted to the trunk of the tree with great 

 accuracy, or they will leave a sort of lubber''s hole through 

 which the insects, who are no seamen, will not fail to crawl. 

 Now to adjust them with such accuracy is a great labor, not to 

 say that it is scarcely possible. But if these difficulties are all 

 overcome, the expedient becomes more liable to the third ob- 

 jection, that of expense. As it is, I believe it is generally 

 considered quite too costly to be applied to orchards contain- 

 ing hundreds of trees, however valuable it may be made for 

 the protection of a few highly prized individuals. 



The remedy most commonly adopted on a large scale is, to 

 place a strip of canvass round the trunk of the tree, and cover 

 it with a coat of tar. This is, perhaps, the cheapest expedient 

 of any, but is certainly dangerous to the tree, as the tar is sure 

 to drip down on the Ijark below. Besides, it is far from a 

 thorough remedy: for a ^ew hours of drying wind will com- 

 pletely harden the surface of the tar, or five minutes of drizzling 

 rain will chill it, and in either case the grub will walk over it 

 with perfect ease. 



I do not know that I can name any expedient possessing the 

 requisites laid down in the beginning. The best which I have 

 seen is that described by Kollar in his book On Insects, and 

 called by him a wooden boot. This is nothing but a box with 

 four sides, but neither top nor bottom, made of a size to go 

 round the tree in the same way in which a circle is circum- 

 scribed by a square. A coving projects all round, on the out- 

 side, like the eaves of a house, and this coving may be two 

 inches or more in breadth. A good workman can make about 

 sixteen of these boots per day. The quantity of stock, which 

 need not be of the best lumber, will vary with the size of the 

 tree. The height, however, need not be more than a foot. I 

 am confident that a tree, of a foot in diameter, could be pro- 

 vided with a box for twenty cents; and such boxes could be 

 made to last as many years, by tacking one side loosely, so 



