INSECTS INJURIOUS TO PEACH, PLUM AND CHERRY 585 



suffer less than unsprayed ones. The best treatment for general 

 use is miscible oil spraying. The oils to be used at about one to 

 16 or 18 and applied in the spring after the buds swell but before 

 they open. Two treatments in successive years must be given to 



FIG. 516. Distribution in the United States of the terrapin scale (Eulecan- 

 ium nigrofasciatum). (After Simanton, I.e.) 



get the full benefit and it is better, in infested regions, to make it 

 an annual treatment. 



The Black Peach-aphis * 



The black peach-aphis is a native species which has been most 

 injurious in the Middle Atlantic States, but has become widely 

 distributed on nursery trees. It attacks the roots, tender shoots 

 and foliage of the peach. When occurring on the roots, trees are 

 often seriously injured before its presence is suspected. Young 

 trees are particularly affected, the injured trees having a yellowish 

 sickly foliage. Usually, however, the presence of the aphids 

 on the young shoots and leaves will be an indication of its inhab- 

 iting the roots also. In the spring and early summer the aphids 

 cluster on the tender shoots at the crotch of the tree and low 

 down on the limbs and soon form a disgusting black mass over 

 the young leaves, which are tightly curled up from the injury. 



