
33 
down by water. Of this sort are the kerosene emulsions and resin 
wash—the former preferable—the potash fertilizers, muriate and 
kainit, and bisulphide of carbon. The simple remedies are in applica- 
tions of strong soap or tobacco washes to the soil about the crown; or 
soot, ashes, or tobacco dust buried about the roots; also similarly 
employed are lime and gas lime. Submersion, wherever the practice of 
irrigation or the natural conditions make it feasible, has also proved 
of the greatest service against the phylloxera. 
EOT WATER. 
As a means of destroying root-lice, and particularly the woolly louse 
of the apple, the most generally recommended measure hitherto is the 
usesof hot water, and this, while being both simple and inexpensive, 
is thoroughly effective, as has been demonstrated by practical experi- 
ence. Water at nearly the boiling point may be applied about the 
base of young trees without the slightest danger of injury to the trees, 
and should be used in sufficient quantity to wet the soil thoroughly to 
a depth of several inches, as the lice may penetrate nearly a foot below 
the surface. To facilitate the wetting of the roots and the extermina- 
tion of the lice, as much of the surface soil as possible should be first 
removed. 
Bya hot-water bath slightly infested stock can easily be freed of 
the aphides at the time of its removal from the nursery rows. The 
soil should be dislodged and the roots pruned, and in batches of a 
dozen or so the roots and lower portion of the trunk should be 
immersed for a few seconds in water kept at a temperature of 130° 
to 150° F. A strong soap solution similarly heated or a fifteen times 
diluted kerosene emulsion will give somewhat greater penetration and 
be more effective, although the water alone at the temperature named 
should destroy the lice. 
Badly infested nursery stock should be destroyed, since it would be 
worth little even with the aphides removed. 
TOBACCO DUST. 
Some very successful experiments conducted by Prof. J. M. Sted- 
man demonstrated the very satisfactory protective, as well as reme- 
dial, value of finely ground tobacco dust against the woolly aphis. The 
desirability of excluding the aphis altogether from nursery stock is at 
once apparent, and this Prof. Stedman shows to be possible by placing 
tobacco dust freely in the trenches in which the seedlings or grafts are 
planted and in the orchard excavations for young trees. Nursery 
stock may be continuously protected by laying each spring a line of the 
dust in a small furrow on either side of the row and as close as possi- 
ble to the tree, covering loosely with earth. For large trees, both 
for protection and the destruction of existing aphides, from 2 to 5 
16871—No. 127—01 3 

