The Tree-Hoppers 



is common all through the United States, from Missouri north- 

 wards into Canada, and is sometimes the cause of considerable 

 damage in orchards, particularly to young trees and nursery 

 stock. The injury is produced by the cutting of the small limbs 

 by the female with her saw-like ovipositor, in which process she 



makes large holes through the 

 bark in which the eggs are in- 

 serted in clusters. The insect 

 flies with a loud buzzing noise 

 from tree to tree and is very shy. 

 The twigs chosen for egg-laying 

 are preferably those of two or 

 three years growth and various 

 kinds of trees are selected. 

 The eggs are placed in small 

 compound groups arranged in 

 two nearly parallel or slightly 

 curved slits. About a minute 

 is required for the insertion ol 

 each egg. The wound is made 

 in such a way as to cause a 

 certain cessation of growth be- 

 tween two rows of eggs to pre- 



Fig. i 3S .-Ceresa bubalus, eggs i and old yent their bejn crushed by the 

 egg-scars. (After Marlatt.) * 



rapid growth of the twig. 



Each female lays from one hundred to two hundred eggs. The 

 insect hibernates in the egg condition and the young hatch in the 

 spring. They molt three or four times before becoming full- 

 grown and during their life feed upon the juices of the tender 

 twigs and leaves by inserting their beaks and pumping up the 

 sap. The insect in its early stages is wingless and is covered on 

 the upper side along the centre with numerous barbed projections. 



240 



