CANEER-WOKM. 113 



or the great majority of them, deposit their eggs within the space of a 

 few inches below the obstruction, then we shall have narrowed down 

 the practical treatment of the Canker-worm to a very small circle. 

 The only remaining necessity will be to dispose of the eggs in such a 

 manner that they shall not hatch, or that the worms proceeding from 

 them shall not ascend the tree. I have proved, by experiment, the 

 truth of what has been stated by others, that polished surfaces, such as 

 tin and glass, furnish no obstacle to the ascent of the young worms. 

 They walk with the utmost ease up a plate of glass, its smoothness be- 

 ing, in their case, simply equivalent to the absence of obstructions. 



The quickest and surest remedy, therefore, is to destroy the vitality 

 of the eggs. It has been found that the eggs of insects will often with- 

 stand much stronger applications than the insects themselves, and I 

 have found that the eggs of the Canker worm moth may be smeared 

 with soft-soap, or wet with a strong infusion of Paris green, without 

 loring their vitality. But the least touch of kerosene oil is invariably 

 fatal to them. By removing the bands, immersing the pieces of rope 

 in boiling water, and applying kerosene to the trunk for a few inches 

 below the band, the greater part of the eggs will be destroyed. To 

 make the work more thorough, it will be necessary to apply the kero- 

 sene over the greater part of the trunk between the band and the 

 ground, as some eggs are found under the bark nearly down to the 

 ground ; and this suggests the propriety of putting the band as low 

 down as convenient, so as to circumscribe as much as possible the 

 space to which the oil is to be applied. 



But it will be asked : Will not the direct application of the kerosene 

 injure the tree ? 



It seems to be generally supposed that certain strong and pungent 

 substances cannot be applied to the bark of trees without injury. Ac- 

 cordingly we find that it has been the common practice in applying tar, 

 especially the coal tar, to the trunks of apple trees, for the purpose of 

 preventing the ascent of the Canker worm moths, to first surround the 

 trunk with a band of coarse cloth, upon which the tar may be received. 

 As it appeared from my experiment, that the strong applications usually 

 made use of to destroy insects, fail to destroy the vitality of the Can- 

 ker-worm eggs, whilst the least touch of kerosene is fatal to them, it 

 became desirable to test this matter, and determine whether the direct 

 application of kerosene oil to the trunk and branches is injurious to the 

 tree. 



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