428 THE MONTHLY BULLETIN. 



These stem mothers are always winged, and like the plant lice of later 

 generations are capable of migrating to other trees and orchards. As 

 soon as they are fully developed they begin to lay young plant lice. 

 This second generation will become mature in three weeks, and in turn 

 produce young. 



The young of the third and subsequent generations of summer mature 

 in about sixteen days. On early leafing varieties there are ten or eleven 

 viviparous generations a year, while on late varieties there are eight or 

 nine. The production of the sexual generation is prolonged over four 

 months, these forms first appearing in July. The fertilized females 

 deposit their eggs on the twigs and limbs of the tree. Winter is passed 

 in the egg stage only. In general these plant lice inhabit the under side 

 of the leaves, but sometimes those of the second, third and fourth genera- 

 tions attack the nuts, often seriously dwarfing them. When the infes- 

 tation on leaves and nuts is severe the vitality of the infested tree is 

 impaired. The lice excrete a sweet, gummy, transparent substance, and 

 on this thrives a black, sooty fungus. This black fungus often covers 

 the upper side, lower leaves, and upper part of the nuts, thereby inter- 

 fering with the respiratory action of the plant tissues. 



The walnut plant lice have many natural enemies, the most persistent 

 of them being the ashy-gray ladybird beetle. The plant lice can be eon- 

 trolled artificially with sprays. The winter spray directed against the 

 eggs is the easiest to apply, and high trees can be reached by a winter 

 wash ^^'ith ease, whereas in the spring and summer the foliage is so 

 thick that a thorough application is hard to apply satisfactorily. 

 Furthermore, far less material is required when the trees are bare. 

 Lime-sulphur and crude oil emulsions are effective, especially the first 

 named. These sprays should be directed all over the limbs and twigs, 

 so as to cover every part. If it is necessary to spray in the spring 

 or summer, a combination of 2 per cent of clistillate oil emulsion and 

 commercial tobacco extract, 1 to 1,500, will prove effective, provided it 

 be applied under a pressure of at least 150 pounds, and the spray 

 directed on the nuts and underside of the leaves. — E. J. Y." 



Spores Carried by Birds. In the Journal of Agricultural Research, 

 United States Department of Agriculture, it is shown that spores of the 

 chestnut blight fungus are carried by birds. Thirty-six birds were 

 examined, on over half of which were found the spores. This is of 

 special interest to us here where pear blight is so destructive. Birds, 

 as well as insects, may be the agents of pear blight dispersion. — A. J. C. 



Bud Selection. W^e have long known of the importance of selec- 

 tion in breeding animals. Today plant breeding is also to the front as a 

 means of promoting our agriculture. The work of A. D. Shamel, of 

 the United States Department of Agriculture, bids fair to become a 

 classic in research work. Mr. Shamel reports that fruit from selected 

 buds three years old was not only 90 per cent first grade, but gave one 

 half box to each picking, while trees of same character not budded — 

 seedlings — gave only one half box per tree for the year, and of this 

 only 25 per cent was first grade. This speaks volumes in favor of bud 

 selection. — A. J. C. 



