Plate XIII. — Insect enemies of the apple. ( 1 ) The 

 fruit-tree leaf-roller egg mass from which the young cater- 

 pillars have hatched; (2) The rounded-headed apple-tree 

 borer in its tunnel at the base of a young apple tree; (3) 

 The oyster-shell scale: (left) scale turned over to show 

 eggs; (middle) mature scale; (right) young scale. 



