Conclusions. 31 



Spraying with kerosene emulsion in winter, after the trees have been 

 pruned, is the best method of destroying the scale in Japan ; the emulsion is 

 effective and cheap, obtained very easily anywhere ; a mixture of 1 part of 

 the emulsion witVi 5 parts of water, applied in winter, kills more than 85% 

 of the scale. 



Many of the localities marked with spots on the map i. e. infested 

 localities are now free from the scale ; and we hope and believe that we shall 

 see a great change in the face of the map showing the distribution of the San 

 Jose Scale in Japan, within a short time. 



XIV. Conclusions. 



Our investigations of the San Jose Scale in Japan since 1900 uiay be 

 briefly summerized as follows : — 



1. Since the writer actually made his report on the wide distribution of 

 the scale in Japan in the summer 1900, a large part of his own time and that 

 of other entomological members of the station has been spent in the investiga- 

 tion of the scale ; the trees in and near suspected orchards, nurseries, parks, 

 private gardens and temple grounds throughout the empire were carefully 

 examined. Special excursions were made through wild and high regions and 

 also sea levels and plains, climbing to several mountains and penetrating into 

 wood land and deep valleys ; the magnitude of the work and amount of labour 

 involved are hardly apparent to those who have not been engaged in work of 

 this kind ; a great many miles have been traveled, and many weeks have been 

 spent in the examination of suspected trees. 



In our investigation of the scale we have found that the distribution of 

 the scale in Japan is very wide ; out of 482 localities in the four main islands 

 it is recognized in 145. 



2. In almost every instance the infested localities trace the introduction 

 of the pest to trees purchased from the well known nurseries. 



3. The scale was introduced into Japan with infested stock in 1871 or 

 about that time from the west. 



4. The purchased original and infested stock was planted at A.woyama, 



