656 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



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

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

 On young trees in the nursery and on young orchard trees, this 

 injury to the foliage is sometimes so severe as to kill or severely 

 check the growth. 



Both winged and wingless aphides are found on the foliage, 

 but only the wingless forms occur on the roots. Both forms are 

 about one-twelfth inch long and shining deep brown or black 

 in color when mature. The partly grown aphides, which form 

 the larger part of most colonies, are reddish-yellow or amber 

 colored. 



N/.7 



X .90 



FIG. 506. The black peach-aphis (Aphis persicce-niger Er. Sm.): winged 

 viviparous female; young female, first instar; apterous ^'"iparous 

 female much enlarged. (After Gillette and Taylor.) 



Life History. The wingless aphides feed and reproduce upon 

 the roots throughout the year, all being females and giving birth 

 to live young after the manner of the aphides. In the spring 

 some of them migrate to the young foliage, often appearing on the 

 tender tw r igs before the buds open. They multiply rapidly, and 

 as a result of the hundreds of little beaks sucking out the juices 

 the shoot soon withers, which causes the young to develop into 

 winged aphides which migrate to other trees. Honey-dew is 

 excreted very freely by the aphides, which are therefore attended 

 by numerous ants which doubtless aid in their transportation 



