REPOET OF THE SECRETARY OF AGRICULTURE. XCVII 



Ever since the appearance of the San Jose scale in the United States 

 the question of its original home has been a mooted one; and, since none 

 of the parasitic and predatory insects of this country seem to be very 

 efficient in destroying this scale, it has become an important point to 

 decide, if possible, the question of the original home of the destructive 

 insect, since it is quite fair to suppose that if efficient parasites are to 

 be found the}" will be found in the original home of the scale. The 

 importance of this quest can hardly be overestimated, since the dam- 

 age which the San Jose scale has done to the fruit-growing interests 

 of the country, especially of the Eastern States, is almost beyond 

 estimate. 



^ The evidence accumulating during the past two or three years nad 

 seemed to show that very possibly this scale was originally imported 

 into this countr}^ from Japan, and in the spring of the present year 

 the assistant entomologist, Mr. Marlatt, was sent to Japan for the 

 purpose of studying the question on the ground. Unexpectedl}^ to 

 most entomologists, although not to the entomological force of the 

 Department of Agriculture, it was quite definitely ascertained that 

 the San Jose scale is not indigenous to Japan, but that, quite to 

 the contrar}^, it was introduced into that country from the United 

 States upon fruit stock at several different times and at several 

 different points. The most careful search failed to reveal the scale 

 in portions of Japan where American plants had not been intro- 

 duced. Mr. Marlatt's travels in the Japanese Empire lasted about five 

 months, and having satisfied himself, as just stated, he proceeded to 

 China, visiting Chefoo, the port of the great foreign fruit district of 

 North China, where the industrj'^ was started by a missionary (Dr. 

 Nevins) some thirty years ago, since which time it has extended over 

 the province. Foreign fruits were introduced and are now grown 

 alongside the native fruits or grafted on native trunks. The San Jose 

 scale was found there, but the admixture of foreign trees with the 

 native trees prevented an}^ conclusion as to whether the scale was 

 indigenous or not. Proceeding to Pekin, he found the fruit markets 

 enormously stocked and representing exclusively the products of the 

 surrounding country and districts south of and adjacent to the Great 

 Wall. All the fruits were native. The apples were small, and the 

 pears were hard and woody. Nearly all this fruit was infested by the 

 San Jose scale. 



At Tientsin the same conditions were found in the fruit markets, 

 and in the cit}^ gardens and private yards the San Jose scale was found 

 on a flowering shrub coming trom North China. In all the region 

 between Tientsin and Pekin and the Chinese wall native fruits only 

 are grown, and no foreign stock of any kind has ever been introduced. 

 Apples, pears, peaches, apricots, and plums are extensively grown on 

 the sunny slopes of all the hills south of the Great Wall. The San 



AGR 1901 VII 



