INSECTS INJURIOUS TO VEGETATION. 445 



noticed they were quiet. The tarring should be continued in 

 the autumn and spring, until the grubs are no longer seen. The 

 strips of. paper sliould then be immediately taken from the 

 trees, and if there be any tar on their trunks it should be care- 

 fully scraped ofl". Some persons are in the haljit of applying 

 the tar directly to the trunk of the tree. This can be done 

 without much apparent injury to an old tree having a rough 

 bark, and providing the tar is all scraped from it early in the 

 spring, or before the heat of the sun has caused it to run down 

 and drip. We would not, however, recommend the direct ap- 

 plication of tar upon the bark, it not being entirely safe, and 

 when we take into view the trouble of scraping it from the tree, 

 it is not a saving of labor. As a general rule, our greatest 

 efforts should be directed in preventing the grub from ascending 

 the trunk of the tree, but something may be done after it has 

 eluded us, and effected its object. If the trees are small and 

 easily reached, by jarring the branches the worms can be made 

 to spin down by their threads, and by severing these with a 

 stick, they will fall to the ground. If this be done when they 

 are small, they will not recover the tree again. In the winter 

 season, upon the hard crust of a deep snow, when a great reflec- 

 tion of light is produced, many clusters of the eggs of the can- 

 ker worm. Lackey caterpillar, and other insects, can readily be 

 discovered and destroyed. 



During a period of twenty-five years, my grounds have been 

 thrice visited by canker worms, and in each instance I have 

 succeeded in preventing their ravages, by tarring the trees, very 

 much in the way and manner narrated in this essay. 



The American tent caterpillar, or Lackey, usually known by 

 the name of the caterpillar, is an insect injurious to the apple 

 tree, and is more generally known than the canker worm. It is 

 a native insect, and probably before the settlement of the coun- 

 try, subsisted upon the foliage of the wild cherry tree. Its habits 

 being entirely different from the canker worm, renders it more 

 under our control, and easily destroyed. This arises from its 

 being gregarious, and forming in large numbers a common web, 

 in the fork of the tree, where they can be found early in the 

 morning, at noon, and in the evening. These habits of the 

 caterpillar it is well to remember when we would make a call at 

 their domiciles. The methods laid down by some of the old 



