eefOeestation on the kationa^l foeests. 
49 
STOCK. 
If large areas are to be reforested, stock should be excluded, and, 
if possible, sheep should be excluded from any plantation as they do 
more damage to coniferous plants than any other animal, goats 
excepted. As a rule, cattle do not damage plantations much, pro- 
vided the ground is not plowed, the area is not close to salting and 
watering places, and the stock is not permitted to concentrate too 
much in particular localities. Fencing against live stock is seldom 
advisable, and where exclusion is necessary it should be based upon 
natural boundaries. 
INSECTS. 
The pine- tip moth has damaged plantations in Nebraska, and the 
white grub of the June beetle cuts off the roots of young planted stock 
in the southwest. No practicable method of combating these insects 
over large areas has been devised. 
Grasshoppers have destroyed whole plantations on the old Kansas 
National Forest, attacking both hardwoods and conifers. Methods of 
control of these insects through burning, poisoning, and trapping 
have been worked out in California,^ but it seems that certain meth- 
ods are effective only with certain species, and control measures must 
accordingly be worked out for each region. i 
DISEASES. 
Diseases in plantations on the National Forests have not been at 
all serious. Were dangerous diseases to appear it might be imprac- 
tical as well as impossible to stamp them out. It is well, therefore, 
to warn against the planting in one general region of nursery stock 
grown in another unless there is absolute certaint}^ that it is not 
affected by diseases which may prove harmful to the native timber 
Where the stock is to be planted. White pine grown in regions where 
the white-pine blister rust is prevalent should not be planted in the 
western white pine and sugar pine regions; and western yellow-pine 
nursery stock produced in a region where mistletoe is present should 
not be shipped, for instance, to the Black Hills where this disease 
does not occur. Great economic losses are possible through the ship- 
ment of diseased or insect- infested stock. 
RODENTS. 
Young planted stock is often damaged by rodents, and tree seed is 
very attractive to them. In many cases it is their natural food, and 
iCal. Agri. Exp. Sta. Bui. 170, " Studies in Grasshopper Control." 
