56 THE GYPSY MOTH APPENDIX. 



the use of it, the most satisfactory results have been ob- 

 tained. It is undoubtedly true that larger proportions of 

 this substance must be used than of Paris green, but this can 

 be done with entire safety to the vegetation. The cost of 

 the insecticide forms a very small part of the cost of spray- 

 ing ; and since arsenate of lead remains on the foliage so 

 much longer than other insecticides, a much larger pro- 

 portion can be used and even then be much cheaper than 

 (substances which wash off readily in showers, making it 

 necessary to spray the trees a second time. 



A large percentage of the spraying done in orchards at the 

 present time is with a mixture of an insecticide and a fungi- 

 cide ; because, as has already been said, the great expense is 

 in the labor, and not in the materials used ; and when the 

 insecticide and fungicide can be applied together, the cost of 

 one spraying is saved. We have not experimented as yet 

 with a fungicide mixed with arsenate of lead, but our chem- 

 ist, Mr. F. J. Smith, informs me that he does not think there 

 will be any reaction between arsenate of lead and the Bor- 

 deaux mixture to prevent using them together, but that they 

 may be mixed and used as readily as Paris green and the 

 Bordeaux mixture. Professor Craig, in his report as hor- 

 ticulturist of the Experimental Farms, 1895, p. 119, records 

 excellent results with arsenate of lead against the codling 



~ o 



moth, and also good success in using the insecticide and 



O O 



Bordeaux mixture together. 



Spraying may almost be regarded as a fine art. Not every 

 one of those even w 7 ho have had a long experience at the 

 work can spray a tree properly. I have repeatedly examined 

 trees which had been sprayed by those who considered them- 

 selves experienced hands at the work, and found the leaves 

 so wet that the water was dripping from them or standing on 

 the surface in such quantity that the poison was settling on 

 the lower part, where it either ran off, or, when the water 

 evaporated, the poison was confined to a fractional portion 

 of the leaf. Spraying should be done with a nozzle that 

 gives only a fine, mist-like spray, and should be stopped 

 before it runs on the leaves. This is more easily said than 

 done, but we often find men who seem to catch the idea, and 

 stop at the exact time. 



