INSECTS INJURIOUS TO AGRICULTURE IN JAPAN O 



the United States, have been introduced into Japan, of which the 

 woolly apple aphis and the scale insects Aspidiotus pemiciosus, 

 Lepidosaphes ulmi, Ceroplastes rwbens, and Front aspis ifanonensis 

 may be cited. A considerable number of other species of importance 

 are believed to have become established in Japan at more remote 

 times, and authentic data are not available regarding their early 

 history in the country. These came largely from China and the 

 South Pacific regions. The oriental fruit moth is presumably to be 

 numbered with this group. 



CLIMATIC CONDITIONS 



The main islands of Japan, with Chosen and Taiwan (see map), 

 present a wide range of climatic conditions, extending from the 

 north-temperate conditions of southern Sakhalin and Hokkaido to 

 the tropical in southern Taiwan. In Hokkaido there is a relatively 

 light rainfall in summer, and heavy snowfall during the winter, 

 the maximum precipitation occurring during this latter period. 

 In Honshu, Shikoku, and Kyushu the maximum precipitation, with 

 a constantly high humidity, occurs during the summer months, 

 from early June to the end of September; and relatively little pre- 

 cipitation occurs during the period from November to April. In 

 the lower elevations of the sections south of Tokyo only occasional 

 light snows occur during the winter, and the temperature drops only 

 slightly below freezing and then for only short periods. On the 

 western coast of Honshu, bordering the Japan Sea, the winter tem- 

 peratures are much lower than on the eastern coast, which is warmed 

 by the Japan Current. In Taiwan the plains area on the western 

 side of the island receives fairly heavy rains throughout the year, 

 with the maximum during midsummer, whereas on the eastern side 

 the rainfall is considerably less. There is a marked difference in 

 the temperature conditions between the northern and the southern 

 sections of the island, particularly during the winter months, much 

 more than would be expected in a range of less than 200 miles of 

 latitude. In Chosen the summers are very hot, and the rains rather 

 excessive during July and August; the winters are cold, but there 

 is little snow. 



In general it may be said that Hokkaido and northern Honshu 

 present climatic conditions similar to those of the North Central 

 States, and southern Japan and Taiwan conditions similar to those 

 of the Gulf States, but that of Chosen has no counterpart in the 

 United States. 



DECIDUOUS-FRUIT INSECTS 



Practically all the data available at the present time regarding the 

 fruit pests of Japan are embodied in bulletins and reports from the 

 various government and provincial experiment stations. In a con- 

 siderable number of cases the specific determination as originally 

 given has been found to be erroneous, and distribution records have 

 had to be revised accordingly. In his recent publication Kuwayama 

 (77) records 121 species of insects as being injurious to fruit trees 

 in Hokkaido alone, and these are listed according to the host plant 

 attacked. Upon apple and pear 88 species are mentioned, with 48 

 upon peach and other species of Prunus, 12 upon grape, and 28 upon 

 mulberry. 



