70 



After returning to Tokyo the orchards between Tokyo and Yoko- 

 hama, which had been visited early in the year and found to be 

 infested with San Jose scale, were again inspected. A few of the trees 

 had been subjected to some treatment during the summer, evidently 

 with soap, and most of the scale insects had been killed either by the 

 soapy treatment or by ladybird enemies or parasites. 



Before leaving Japan opportunity was afforded to explore another 

 interior mountain district, viz, the great mountain plateau known as 

 the Hakone region, and a week was spent going by jinrikisha and chair 

 and on foot over these volcanic mountains. The native settlements 

 are largely about Hot Springs, which have become famous as Japanese 

 and foreign health resorts. No evidence whatever of the San Jose 

 scale was found throughout this region, and the scale insects collected 

 were few in amount and variety. In all this region there were old 

 cherry trees and pear trees in house yards, but no orchard plantings 

 of any amount. 



It is impossible in this summary to give the detailed facts on which 

 the decision as to the non-origin of the San Jose «cale in Japan 

 is based. Nevertheless, perhaps enough has been said to give a fair 

 idea of the prevalent conditions. In a general way, it may be stated 

 that wherever the San Jose scale was found in Japan the evidence was 

 very plain that it had been brought in recently on young nursery 

 stock. Very often in south Japan, where the introduction of new 

 stock is of recent beginning, the San Jose scale is still confined to 

 the introduced stock, or has spread very slightly to the old native 

 trees, notably the native Japanese pear. In no case was the San 

 Jose scale found on these native trees where there was not ample 

 opportunity for its having come to them from new stock. In north 

 Japan the apple industry is fi'om twentj^ to thirty years' standing, and 

 is entirely new to Japan, as already indicated, the stock having prac- 

 tically all come from California. Furthermore, the chief sources of 

 nursery supplies in Japan are three establishments, located one near 

 Kobe, another near Yokohama, and the third near Tokyo. Two of 

 these I investigated personally and found to be infested with San Jose 

 scale. The infestation was on the nursery trees, and also on older 

 trees left in the general disposal of stock. In nearly every case in 

 south Japan where the San Jose scale was found it was on stock 

 obtained from one or other of these three nurseries, and the origin of 

 the scale was perfectly plain. In northern Japan the introduction of 

 foreign trees twenty-five or thirty years ago has given this scale a 

 much wider and more general range, but even here wherever you get 

 away from young orchards and new plantings the scale disappears. 

 That, therefore, the San Jose scale came to Japan on American stock, 

 and is a new enemy there of fruit trees, can not be questioned. 



