586 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



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 aphids 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 aphids, which form 

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

 colored. 



Life History. The wingless aphids feed and reproduce upon 

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



1 



FIG. 517. The black peach-aphis (Aphis persicoe-niger Er. Sm.): winged 

 viviparous female; young female, first instar; apterous viviparous female 

 much enlarged. (After Gillette and Taylor.) 



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

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

 tender twigs 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 aphids which migrate to other trees. Honey-dew is 

 excreted very freely by the aphids, which are therefore attended 

 by numerous ants which doubtless aid in their transportation 

 from tree to tree and from the roots to the leaves and back. 

 " During summer the aphids for the most part are to be found 



* Aphis persicce-niger Er. Sm. Family Aphididae. See C. P. Gillette, 

 Bulletin 133, Colo. Agr. Exp. Sta., p. 37; A. L. Quaintance, Journal of Eco- 

 nomic Entomology, Vol. I, p. 308, Yearbook U. S. Dept. Agr., 1905, p. 342. 



