14 



The borer of the apple-tree, a white worm or grub, 

 devours the fragments of wood it has gnawed in 

 making its cylindrical path within the trunk of the 

 tree, and pushes the undigested refuse out of the hole 

 by which it has entered. When fully grown it be- 

 comes a pupa, which, like that of the dorr-bug, ex- 

 hibits short, folded legs, wings, and horns, of no use to 

 it while within its burrow. Early in June the pupa- 

 skin is ruptured, and the insect emerges from the tree 

 by gnawing through the thin covering of bark that 

 protected the upper extremity of its hole. Upon 

 issuing into the air it is found to be a beetle,* white 

 beneath and longitudinally striped with brown above. 

 In this, its perfect state, it hves only upon the young 

 and tender leaves of the apple and other alHed trees. 



The caterpillars of the apple-tree, which are hatched 

 from those curious ring-like clusters of eggs surround- 

 ing the young twigs, are, as you well know, furnished 

 with jaws, and devour the leaves of this tree. They 

 have also sixteen legs, and, in crawling from leaf to 

 leaf and branch to branch, spin from their lips a dehcate 

 thread, which is a clue to conduct them back to the 

 shelter of their many-coated, silken tents. From the 

 first to the middle of June they descend from the 

 trees, and seclude themselves in various hiding-places. 

 Each one then weaves around its body a small silken 

 shroud or cocoon, fills the meshes with a yellowish 

 powder, slips off and packs in one end of its case its 

 old coat, and appears in a new form, that of a brown 

 chrysalis or pupa devoid of prominent legs and 

 wings. Sixteen days afterwards the pupa-skin is rent, 



* Saperda bivittaia. Say. 



