ORCHARD, GARDEN, AND FIELD INSECTS 127 



Although this scale is a very minute animal, yet so rapidly 

 does it multiply that it is very dangerous to the tree. 

 Never allow new trees to be brought into your orchard 

 without positive knowledge that they are free from the 

 scale. If, however, this scale should in any way gain 

 access to your orchard, you can prevent its spreading by 



FIG. 120. SAN Jos SCALE FIG. 121. SINGLE SAN Jos6 SCALE 

 From a drawing furnished by the (Magnified.) From an engraving furnished by 



United States Department of 

 Agriculture 



the United States Department of Agricul- 

 ture 



thorough spraying with what is known as the lime-sulphur- 

 salt mixture. This mixture has long been used on the 

 Pacific coast as a remedy for various scale insects. When 

 it was first tried in other parts of the United States, the 

 results were not satisfactory, and its use was abandoned. 

 However, later experiments with it have proved that this 

 mixture is thoroughly effective in killing this scale, and 

 that it is perfectly harmless to the trees. Until its utility 



