LEPIDOrTERA. 3G7 



loosened soil, these animals will eat many of the chrysalids as 

 well as the corn, and will crusii others witli their feet. Mr. S. 

 P. Fowler* thinics it better to dig around the trees in July, 

 while the shells of the insects are soft and tender. He and 

 Mr. John Kenrick, of Newton, Mass., advise us to remove the 

 soil to the distance of four or five feet from the trunk of the 

 trees, and to the depth of six inches, to cart it away and re- 

 place it with an equal quantity of compost or rich earth. In 

 this way, many of the insects will be removed also; but, unless 

 the earth, thus carried away, is thrown into some pond-hole, 

 and left covered with water, many of the insects contained in 

 it will undergo their transformations and come out alive the 

 next year. 



Canker-worms are subject to the attacks of many enemies. 

 Great numbers of them are devoured by several kinds of birds, 

 which live almost entirely upon them during their season. 

 They are also eaten by a very large and splendid ground-beetle 

 [Calosoma scrutator), that appears about the time when these 

 insects begin to leave the trees. These beetles do not fly, but 

 they run about in the grass after the canker-worms, and even 

 mount upon the trunks of the trees to seize them as they come 

 down. The potter-wasp (Eumenes fraterna), an insect rather 

 smaller than the common brown wasp, fills her clay cells with 

 canker-worms, often gathering eighteen or twenty of them as 

 food for her young.f A four-winged ichneumon-fly also stings 

 them, and deposits an egg in every canker-worm thus wounded. 

 From the egg is hatched a little maggot, that preys on the 

 fatty substance of the canker-worm, and weakens it so much 

 that it is unable to go through its future transformations. I 

 have seen one of these flies sting several canker-worms in 

 succession, and swarms of them may be observed around the 

 trees as long as the canker-worms remain. Their services, 

 therefore, are doubtless very considerable. Among a large 



* See "Yankee Farmer" of July 18, 1810, and " New England Farmer" of 

 June 2, 1841, for some valuable remarks by Mr, Fowler. 



t See the history of this insect, and a figure of her cells, in the " Boston Culti- 

 Tator," for July 15, 1848. 



