5 
effective, as has been demonstrated by practical experience. 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 thoroughly wet the soil 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 extermination of the lice, as 
much of the surface soil as possible should be first removed. 
Some recent very successful experiments conducted by Mr. J. M. 
Stedman have demonstrated the very satisfactory protective as well 
as remedial value of finely ground tobacco dust. The desirability of 
excluding the aphis altogether from nursery stock is at once apparent, 
and this Mr. Stedman has shown 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 possible to the 
tree, covering loosely with earth. For large trees, both for protection 
and the destruction of existing aphides, from 2 to 5 pounds of the dust 
should be distributed from the crown outward to a distance of 2 feet, 
first removing the surface soil to a depth of from 4 to 6 inches. The 
tobacco kills the aphides by leaching through the soil, and acts as a 
bar for a year or more to reinfestation. The dust is a waste product of 
tobacco factories and costs about 1 cent per pound, and possesses the 
additional value of being worth fully its cost as a fertilizer. 
The use of bisulphide of carbon for the woolly aphis is the same as 
for the grape root-louse. It should be applied in two or three holes 
about the tree to a depth of 6 to 12 inches and not closer than 14 feet 
to the crown. _ An ounce of the chemical should be introduced into 
each hole, which should be immediately closed. The bisulphide evap- 
orates and penetrates throughout the soil and readily and promptly kills 
the aphides. It does not, however, furnish any protection from future 
attacks, and is attended with danger to the tree unless the precautions 
named are carefully observed. That it is highly inflammable should 
also be constantly borne in mind. If it is to be used at all extensively, 
an automatic injecting device should be secured, such as the McGowen 
injector. The chemical costs 10 cents per pound in 50-pound cans of 
the manufacturers. 
Badly infested nursery stock should be destroyed, since it would be 
worth little even with the aphides removed. 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 180° to 150° F. A strong soap solution similarly heated or a fifteen 
