are smaller than an ordinary pin-head in diameter and 

 are quite flat (See PI. I, figs. 2 and 3). The scales are 

 hardly more than 1-25 inch across and many of them are 

 smaller still. Beneath the scale the body of the insect 

 may be found as a small, immovable, yellow body (if still 

 alive) which if crushed seems to be filled with a rather 

 thin, yellow, oily liquid. The young of this species are 

 born alive and their powers of reproduction are so re- 

 markable that a tree bearing but few live scales in the 

 Spring may become quite heavily infested by Fall and will 

 then be liable to severe injury during the following sea- 

 son unless some method of destroying the scales is used 

 during the winter. 



Close observation with the naked eye shows that the 

 scales are marked with rings of light and dark gray 

 around a nearly black center. When very abundant they 

 give a general ashy-gray appearance to the entire bark 

 which is noticeable at some distance from the tree. 



Nature of the Injury. — On living infested branch- 

 es, especially on growth two or more years old, the sur- 

 face becomes irregularly pitted or has depressions in 

 spots where the scales are most abundant. The injury is 

 of two kinds. Much sap is abstracted by the myriads of 

 sucking insects, but more important than this is the ef- 

 fect which these scales have of causing a thickening of 

 the cell walls which are penetrated by their slender mouth 

 parts. This thickening checks the flow of sap in the 

 branches, and this means the ultimate starvation of the 

 parts of the branch beyond. The San Jose produces a 

 distinctive red stain around the point of attack, either 

 upon infested fruit or just under the scale in the bark. 

 This appears upon lightly scraping off the outer bark. 



Necessity for Treatment. — So serious is the injury 

 of which this scale is capable that untreated, infested 

 trees are certain to be killed within a very few years. 

 The LIFE OF THE ORCHARD IS AT STAKE and the 

 plain conclusion is evident that it is far more expensive 

 to allow the trees to be destroyed than it would be to con- 



