REMEDIES AGAINST THE CANKER-WORM. 469 



worms after they were hatched from the eggs, and were dis- 

 persed over the leaves of the trees. It is said that some 

 persons have saved their trees from these insects by freely 

 dusting air-slacked lime over them while the leaves were wet 

 with dew. Showering the trees with mixtures that are 

 found useful to destroy other insects has been tried by a few, 

 and, although attended with a good deal of trouble and ex- 

 pense, it may be worth our while to apply such remedies 

 upon small and choice trees. Mr. David Haggerston, of 

 Watertown, Mass., has used, for this purpose*, a mixture of 

 water and oil-soap (an article to be procured from the manu- 

 factories where whale-oil is purified), in the proportion of 

 one pound of the soap to seven gallons of water ; and he 

 states that this liquor, when thrown on the trees with a 

 garden engine, will destroy the canker-worm and many other 

 insects, without injuring the foliage or the fruit. This ap- 

 plication may be found useful in protecting grafts ; for if 

 canker-worms attack these, they will very much injure, if not 

 entirely destroy them. Jarring or shaking the limbs of the 

 trees will disturb the canker-worms, and cause many of 

 them to spin down, when their threads may be broken off 

 with a pole ; and if the troughs around the trees are at the 

 same time replenished with oil, or the tar is again applied, 

 the insects will be caught in their attempts to creep up the 

 trunks. In the same way, also, those that are coming down 

 the trunks to go into the ground will be caught and killed. 

 If greater pains were to be taken to destroy the insects in 

 the caterpillar state, their numbers would soon greatly di- 

 minish. 



Even after they have left the trees, have gone into the 

 ground, and have changed their forms, they are not wholly 

 beyond the reach of means for destroying them. One per- 

 son told me that his swine, which he was in the habit of 

 turning into his orchard in the autumn, rooted up and 

 killed great numbers of the chrysalids of the canker-worms. 

 Some persons have recommended digging or ploughing un- 



