98 



FARM FRIENDS AND FARM FOES 



often destructive, is the Mourning Cloak Butterfly, the 

 caterpillars of which frequently defoHate willow, poplar, 

 and elm trees, so that in some localities they are called the 

 Spiny Elm Caterpillars. 



An even more generally destructive butterfly is the larg- 

 est of our North American forms, called the Cresphontes 

 Butterfly. This is a Southern species, being, however, 

 widely distributed as far north as Massachusetts, New 



Oranue-dog Caterpillars 



York, and Illinois. Throughout the orange-growing re- 

 gions, the caterpillars are commonly known as " Orange- 

 dogs," because they feed so largely upon the leaves of 



