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upon examining the roots, we found the black aphides as I had pre- 

 dicted. None of these gentlemen had ever seen or heard of this 

 insect, nor could I find any Michigan peach grower who was better 

 informed. There were not many cases at either place, and all of 

 them were young trees recently introduced from New Jersey. 



This aphis seems to be a native of the United States. I can 

 find no account of it, or of anything like it, in European literature. 

 It is by far the most abundant of our peach aphides. In compari- 

 son, Myziis persic(S is very rare. I believe this insect was confined 

 originally to some native plant, and has migrated from that to the 

 peach, finding the latter more congenial. If so, what is this wild 

 plant ? As stated already, careful search on the tops and roots of 

 many weeds proved fruitless. Additional examinations of hundreds 

 of cherry trees made in the worst infested peach districts of Mary- 

 land and Delaware, since the writing of Part I, brought to light no 

 new facts. There were some colonies of Myziis cerasi, but none of 

 this insect. 



I did find it, however, upon the wild Priiyius chicasa, and on 

 the cultivated wild goose plum. This was in Kent County and 

 Caroline County, Maryland, in May, but after the first part of this 

 paper was in type. I also saw it sparingly on Damsons and other 

 types of plum. On Prumis chicasa it was common on the roots as 

 well as the branches. From what was seen at that time and gathered 

 by inquiry, I infer that it is as much at home on the Southern wild 

 plum and its cultivated varieties as it is on the peach, but that it at- 

 tacks other types of plum only exceptionally. It is possible, there- 

 fore, that Priiyuis chicasa was the original food-plant of this injurious 

 insect, and that it has migrated to the peach in recent times. 



The practical point for the fruit grower is to know how to de- 

 stroy the insect. ^ 



There is probably no certain way of reaching the aphis under 

 ground, although some claim to have driven them away by the use 

 of very strong stable manure. When the trees have been stunted, 

 the best thing is to pull them out and plant others. I have some- 

 times thought an insecticide bath might be provided for dipping the 

 roots of suspicious trees before planting, but I have no suggestions 

 to offer. 



When the insect is on the parts above ground it can be disposed 

 of effectually by procuring a force pump with a cyclone nozzle and 

 spraying the foliage with insecticides. 



Charles Wright, of Seaford, Del., saved his nursery last Spring 

 by the application of strong tobacco water. One spraying sufticed. 



