O The San Jose Scale in Japan. 



S. I. Kuwana, assistant in entomology, department of zoology, Leland 

 Stanford Jr. University, California at that time, took a trip to collect scale 

 insects in Japan during three Summer months, June, July and August 1900. 

 His observation on this trip distinctly proved for the first time the wide 

 propagation of the scale throughout the empire , many nursery men and 

 fruit-growers learned much about the scale from him, and immediate interest 

 and attention were secured. 



A German Imperial ordinance prohibiting entirely the importation of all 

 plants, fruit-trees and seeds, except water plants and bulbs, from Japan was 

 promulgated on Aug. 16th 1900 ; This prohibition struck the exporters 

 severely. 



In the early part of April 1901, Mr. C. L. Marlatt, the fiL-st assistant 

 entomologist, U. S. Department of agriculture, took a trip to Japan and spent 

 here six months ; the purpose of his trip was to look for the natural enemies 

 of the San Jose Scale, and his exploration of the interior of the country was 

 pretty through for a foreigner. After his return to his native country he 

 reported many interesting facts in regard to the scale in Japan. The in- 

 vestigations of Kuwana and Marlatt, however, could not be as complete as 

 they ought to have been, for they were limited as to time. The entomologi- 

 cal division of our station took up the subject and made a more complete 

 investigation of the matter ; the following pages are the result of our work 

 up to date. It is by no means perfect as yet, nevertheless, we believe that it 

 will be, no doubt, very useful to the authorities outside of the empire, and 

 will decide the question which lies before the scientific and practical world. 



III. Horticultural conditions in Japan. 



Any one who makes a study of the San Jose Scale in Japan, in order to 

 observe the spreading of the scale through the country, will have to consider 

 the past and present conditions of horticulture in Japan ; without the know- 

 ledge of this industry no one can help forming a misconception in regard to 

 the subject. 



The principal fruits cultivated in early days were the native pear, per- 



