QUESTION DRAWER. 



Reply by Prof. H. L. Hull, O. A. C".. 

 Guelph. 

 Coal ashes are of little or no value as 

 a fertilizer. The elements of greatest 

 value in wood ashes are potash and 

 phosphoric acid, the percentage of 

 which varies greatly according to the 

 kind of wood from which the ash is 

 taken. Analyses made in the Chemical 

 Department here last year, of the ash 

 taken from difTerent trees, showed that 

 cedar ash contained only 3 30% of pot- 

 ash and .98% phosporic acid, while elm 

 ash contained 35. 37% of potash and 

 •45% of phosphoric acid. If you can 

 get plenty of good wood ashes you will 

 have no necessity for buying phosphoric 

 acid or nitrate of soda. The principal 

 element of fertility in the hair and flesh- 

 ings would be nitrogen, which, however, 

 would be largely liberated and lost if 

 mixed with much lime. The best way 

 to use such material would be to com- 

 post it with a large amount of earthy 

 matter, which would retain the am- 

 monia as liberated by the action of the 

 lime. Apply the compost as a top 

 dressing for some field or garden crop. 



To Destroy Ants. 



949. Sir, — What is tlie best method of 

 preventing yomig ants going up young plnm 

 trees, and what will drive them entirely out 

 of the ground? I find them very destructive 

 to the young tree?. I have tried using a rag 

 about the trees, soaking it with coal tar, but 

 that soon dries up. 



Tuos. NoRKis, Parin. 



Reply hy Dr Jas Fletcher, of the Central 

 Experimental Farm, Ottawa, Ont. 

 I shall be interested to hear from Mr. 

 Norris, how he thinks that young ants 

 injure his young plum trees, I have 

 never in my experience seen any injury 

 to trees by ants, and I am much more 

 inclined to think that their presence on 

 Mr. Norris's plum trees merely indicates 

 that his trees are infested by plant lice 

 or scale insects. It is just possible that 



ants may sometimes do harm by mak- 

 ing their nests under the roots of trees, 

 but I am not sure even of this, although 

 I receive very many reports from fruit 

 growers to this effect. The relations 

 between ants and the aphidas or plant 

 lice are well known and have been most 

 delightfully described by Sir John Lub. 

 bock in his book " Ants, Bees and 

 Wasps." The plant lice are actually 

 kept on trees and bushes by ants, so 

 that they may feed on the honey-dew 

 which is secreted by the plant lice, in 

 fact they serve them as cows and have 

 been called "Ants' cows." Some spe- 

 cies of ants collect root-feeding plant 

 lice and carry them into their nests, 

 and not only do they protect them in 

 this way, but they actually collect their 

 eggs in the autumn and take care of 

 them carefully in their nests during the 

 winter. Many other insects are also 

 domesticated by ants, and Sir John 

 Lubbock says " It is not going too far 

 to say that ants have domesticated more 

 animals than we have." I would advise 

 Mr. Norris at once to examine his trees 

 and see if they are not infested with scale 

 insects, or whether he does not find 

 upon the twigs the small black eggs of 

 plant lice. If he does find either of 

 these the trees should be at once spayed 

 with kerosene emulsion. 



A Scale Insect of the Maple Tree. 



949. .Sir, — I enclose you a twig of a 

 ilaple tree covered with a scale insect, for 

 identitication. \V. 



Reply by Dr. Jas. Fletcher, of the Central 

 Experimental Farm, Ottawa, Ont. 



Dr. Howard first described this insect 

 as Lecanium persica;, but he has since 

 decided that it is a new species, Lec- 

 anium patelliforme. It can be destroyed 

 by spraying the trees, once before the 

 buds burst, with kerosene emulsion. 



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