254 STATE HORTICULTURAL SOCIETY. 



It proves ironclad against the arsenites and kerosene emulsion, and the 

 only effectual remedy is hand-picking in the cool of the day. The use of 

 carbolic acid as recommended for the plum curculio seems to be distasteful 

 to the beetles and tends to drive them away. Clean cultivation undoubt- 

 edly tends to destroy them to some extent, as they pupate in the soil. 



THE APHIDES OF PEACHES AND PLUMS. 



Both fruits are often injured by plant-lice. The foliage of the plum is 

 attacked by the so-called plum-tree aphis {Aphis prunifolia, Fitch), 

 while the peach tree aphis {Myzus persicae, Sulzer) attacks the leaves 

 and twigs of the peach, and the black peach aphis {Aphis persicae-niger. 

 Smith) attacks roots, leaves, and tender shoots. 



The plum tree aphis, when first hatched, is of a greenish- white color, 

 but it soon grows darker, and later in the season becomes nearly black. 

 Like other plant lice, these insects obtain their food by sucking the juice 

 from the leaves and young shoots. This tends to weaken the plants and 

 the leaves become more or less blistered, and finally roll up. If the attack 

 is severe they may drop from the trees. 



The eggs are deposited upon the branches, at the base of the buds, or in 

 cracks in the bark, in the fall. The insects are hatched about the time the 

 buds open in the spring. The first brood consists entirely of females, 

 which develop in ten or twelve days, after which, for some three weeks, 

 they give birth to about two young aphides daily, and then they die. 

 This is repeated by the successive broods until cold weather approaches, 

 when both males and females are produced. After pairing, the females 

 deposit eggs as noted above. 



These insects obtain their food by sucking the juice of plants through 

 their long, slender beaks. It will be seen that they can not be destroyed 

 by the use of arsenites, and some remedy must be employed that will kill 

 by contact. 



For the aphides upon our fruit trees we have no better remedy than 

 kerosene emulsion, although tobacco water, soap suds, and pyrethrum in 

 water are valuable. 



The peach-tree aphis works in about the same way as does the plum 

 aphis, and the same remedies should be employed. Like the plum aphis, 

 some of the females and also the males are winged, to permit them to seek 

 fresh pastures after one has been fully occupied. The winged females are 

 nearly black in color and about an eighth of an inch in length, while the 

 wingless individuals are of a yellowish- red color. The males are yellow 

 with brown markings. 



The black peach aphis has been very destructive in the eastern states, 

 where it is found in large numbers upon the branches in the spring, often 

 killing outright small trees and the younger branches of the older ones; they 

 have destroyed entire orchards in some localities and are particularly 

 troublesome to the young trees in nursery rows. They are dark brown or 

 black in color, and have unusually large beaks. 



As noted above, this aphis also feeds upon the roots of the trees, and upon 

 sandy soil it is particularly destructive. Dr. E. F, Smith, who first dis- 

 covered its workings, attributes to it many so-called cases of yellows. The 

 trees made a weak growth, the leaves were yellow and shrivelled, but none 

 of the distinctive features of yellows were present. The fact that this 

 insect has an underground existence favors its development, as it is out of 



