290 STATE HORTICULTURAL SOCIETY. 



dwarfed growth. Six of the most badly affected trees were dug out and 

 examiued very carefully. They were all much dwarfed, the trunks at the 

 collar being only about 3 inches in diameter, although four years old (five 

 years from bud). I saw no root aphides, but each of these six trees was very 

 baiily infested by borers. From one trunk I removed seven, and from none 

 did I take less than two. Three of the trees were entirely girdled ; two were 

 very nearly girdled; and the other had sound bark on less than one-third of 

 its trunk circumference at the collar. 



This is the only instance discovered v/here a growth strikingly like yellows, 

 if not identically the same, seemed to be closely associated with borers. The 

 evidence in this case is, of course, not conclusive. I had my doubts about 

 some of these trees in 1887, and revisited the orchard to settle them. More- 

 over, in 1888, in this block I found undoubted yellows in one tree, a small 

 Mountain Rose replant of 1887, or possibly 1886. This bore spotted, prema- 

 ture peaches but healthy spring foliage and no diseased shoots. I also saw 

 yellows in another young orchard in that vicinity which I know to have been 

 free in 1887. 



INJURIES BY ROOT APHIDES. 



An aphis corresponding nearly to Koch's figures and description of Aphis 

 Chrysanthemi is frequently found upon the roots of peach trees, especially in 

 New Jersey, Maryland and Delaware. It is, I think, identical with a form 

 occurring upon the shoots and young foliage. This, however, I have found 

 only twice in two years, and then but sparingly, and not in the perfect state. 

 No one appears to have collected the winged insect, and it is possible it may 

 prove a distinct species. 



This insect has been known to New Jersey peach growers more than fifty 

 years, and has been on the Delaware and Chesapeake peninsula fully as long. 

 It was at Chestertown, Md., in 18C0, and destroyed thousands of trees in 

 various parts of Kent county between that date and 1875. 



James S. Harris, of Still Pond, states that he has been familiar with this 

 insect for many years, and until recently has lost more trees by it than by 

 yellows. 



At Chestertown in the orchard of Colonel Wilkins it was particularly des- 

 tructive in 1874 and 1875. In 1875 an orchard of 15,000 Early Beatrice 

 hardly 300 of the original trees remained, there having been successive plant- 

 ings to the number of nearly 20,000 on account of injury by aphides. 

 • This aphis was also very abundant at Denton, Md., in 1874 and 1875 and 

 at Bridgeville, Del., about the same time. Thousands of young trees were 

 killed or badly injured. Probably it was destructive in many other parts of 

 the Peninsula at this time. 



This aphis has also proved a great pest to orchards and nurseries in various 

 parts of New Jersey. But I have heard no complaint from western New 

 York or Miciiigan. ^ 



As already noted stunting is one of the marked symptoms of the presence 

 of this aphis. If trees are much dwarfed, and there are no injuries by borers, 

 aphides are almost certain to be found upon the roots. It is not uncommon 

 to find trees which are only one-half or one-third the size of their fellows 

 solely because their roots are infested by this aphis. Sometimes the second 

 or even the third year after planting they are but little larger than when set. 

 As a rule young trees suffer more than old ones. In some instances, especial- 



