PROCEEDINGS OF THE ANNUAL MEETING. 345 



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kill the young stink-bugs with a strong kerosene emulsion, but it is 

 better to get these old fellows in the spring; it is an easy matter to get 

 them out. I do not know of any way to get at them with insecticides. 



Q. How do you manage the climbing cut- worm? 



Prof. Slingerland: They were very ably discussed in one of the Michi- 

 gan bulletins. In New York state, and I think it is true in Michigan, you 

 can keep them off from the trees by a band of cotton or wool tied or bound 

 to the trees. You can either hand-pick them out of the earth at the base 

 of the tree, or you can poison them there. A poisoned bran-mash of 

 arsenic is very good. The worms will eat that in preference to anything 

 else. 



Prof. Taft: Supposing the trees are all taken out clean, how soon 

 would you dare to plant? Give us your idea. 



Prof. Slingerland: I should hesitate to plant before two years, any 

 way, I think. I should not plant the next year, because I believe the ants 

 have a good deal to do with the matter. We know that the ants take care 

 of the root aphis. The louse depends entirely upon the ants to keep it 

 over winter. You can plant other kinds of trees in the same soil — cherry 

 or plum or anything like that, and it will not affect the roots. The ques- 

 tion was brought up today whether they work on old trees. I think you 

 will find the lice on old trees, but they are not destructive to them. You 

 will find the most of them on young trees; that is where they do most 

 of their damaging work. 



Q. Is there any danger in the moving of the young trees that have the 

 aphis on the roots, of the aphis remaining in the ground and being 

 propagated? 



Prof. Slingerland: You get rid of all the insects there happen to be on 

 the tree when you remove it, but I think those that are left in the ground, 

 some of them, would get upon other trees. The ants would carry them 

 there, or they would get there some way. 



Q. Give us a description of the foliage of an infested young tree? 



Prof. Slingerland : I could not tell trees infested with root lice until I 

 pulled them up. 



Q. The foliage, I mean. 



Prof. Slingerland: I do not believe any one can tell sure whether a 

 tree has lice on it unless it shows the lice. There is a very curious and 

 interesting relation between ants and plant lice, and the former do take 

 care of the latter to a great extent. They will protect the lice from their 

 enemies; the ants will fight them off. The ants you see climbing up your 

 trees are going up there to get at these plant lice to get the honeydew they 

 secrete. I do not know that we have any ants that are injurious to trees 

 here at the north. 

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