10 



heavily infested orchards, however, one may find three or four mines 

 to a leaf, and 25 per cent, to 30 per cent., or even more, of the leaf sur- 

 face is destroyed. From both kinds of injury, in the course of two or 

 three seasons the trees in heavily infested orchards become unthrifty 



Fig. 7. Injury to apple foliage by the feeding of the adult 

 beetles in midsummei-. The beetles may. when sutfl- 

 ciently abundant, make li\ce-\vork of the foliage. 



and incapable of a vigorous growth or the production of fruit buds. If 

 the attack continues the lower limbs die, since these are always much 

 more severely injured than the upper ones ; the tree is more susceptible 

 to the effects of late spring frosts or other adverse conditions ; and the 

 orchard. becomes generally unprofitable. (See Figure 10.) 



