340 More of Ca^iker- Worms, 



always get rid of them thus. They increase very fast. Plough very shal- 

 low, so that you can freeze them. They come up with the first warm weath- 

 er." I am not sure the doctor is correctly reported; but I think the quota- 

 tion contains the substantial facts. 



Jonathan Hugjins of Woodburn stated at a meeting of the Alton Hor- 

 ticultural Society, that his own orchards and grounds were entirely free 

 from canker-worms ; whilst his neighbors, separated from him only by the 

 public road, had many apple-trees badly infested by them. He attributed 

 his exemption to the fact that he kept his grounds clean by cultivation, 

 whilst his neighbor's orchard was neglected. 



Hence I believe, that, with our soil and climate, late ploughing will prob- 

 ably be a sufficient remedy for the canker-worm. How it will answer else- 

 where, I am not so confident. In more northern localities, late ploughing, 

 or indeed the ploughing of orchards at all, except while young, may be 

 injurious in preventing the perfect ripening of the new wood. In sandy 

 soils, the caterpillar may penetrate deeper, and not be disturbed by the 

 plough ; or, if disturbed, may be less exposed. 



It is a good rule to attack all noxious insects at that point in their devel- 

 opment where they can be destroyed by wholesale methods ; and this is 

 generally in the larva or pupa state, as they are then less active, and in 

 more uniform conditions. 



Clean culture is a good general preventive against many of our orchard- 

 insects. The apple-borer, the peach-borer, the curculio, and the canker- 

 worm are more numerous in neglected grounds. 



Since writing the above, I find the following rather contradictory evi- 

 dence in " The Iowa Homestead," by William P. Lippincott of Vernon, 

 la. I add it as a corrective. 



" A few years after this, the canker-worms made their appearance in the 

 orchard ; and this proved to be the most troublesome pest of all. The 

 books and papers, some of them, recommended ploughing late in the fall. 

 After trying this four or five years, it was found that this was the very best 

 way to assist their propagation, as it left the ground full of harbors for the 

 next year's breeding. . . . 



"Then, next, the hogs were turned into the orchard ; and this extermi- 

 nated the worms ; and they cannot come back while the hogs are there." 



Alton, III., October, 1869. 



