Canker - Worms. 209 



CANKER-WORMS. 



By R0BIRT Manning, Salem, Mass. 



There are some parts of the country which have, fortunately for the 

 apple-growers, never been afflicted with a visitation of canker-worms ; and 

 it is to be hoped that they may remain in blissful ignorance of this destruc- 

 tive insect. Owing to the female being without wings, it does not extend 

 rapidly ; and, where known, it appears and disappears at irregular and un- 

 certain intervals. In the latter part of the last century, they ravaged the 

 orchards in the north part of Essex County, Mass., until a late hard frost 

 destroyed them, and with them nearly the whole crop of apples. Early in 

 the present century they again appeared, and were again destroyed by a 

 frost in the cold season of 1816. Since that time, they have not generally 

 prevailed until about 1856. In the vicinity of Boston, they were very de- 

 structive from 1 83 1 to 1840, increasing yearly until the last date, when 

 they almost wholly disappeared till 1847, when they again began to increase 

 until many orchards were ravaged by them. The first time I ever saw one 

 was in the autumn of 1856 ; and, though I had given no special attention 

 to their study, I knew it at once as a man instinctively knows his mortal 

 enemy. It was a sluggish-looking insect, apparently unable to crawl up a 

 tree : yet its imbecility was only apparent ; for many of them do crawl up in 

 spite of every obstacle that the lords of creation have contrived to hinder 

 them. 



As they appear every year in localities where they have never been known 

 before, some account of their habits, and the best known preventives of 

 their ravages, will be of interest. These preventives should be applied 

 during the latter part of the present month and through the next. 



The female is a wingless grub, from three-eighths to half an inch in 

 length, with six legs, of a grayish color, resembling the bark of the tree so 

 much, as not to be easily seen on it. When crushed, the abdomen is found 

 to be full of eggs. The male is a moth, with large, thin, silky wings, ex- 

 panding about an inch and a quarter : its body is of the same length as 

 that of the female, but slenderer. They both begin to come out of the 

 ground in the latter part of October, and continue until the ground freezes 



