THE PAEASITES OF POPILLIA JAPONIC A 51 
Sapporo more nearly approximate those of the infested area than do 
those at Yokohama and at Suigen. 
AGRICULTURE AND NATURAL LANDS OF JAPAN AND CHOSEN IN 
RELATION TO POPILLIA 
Since agricultural and natural conditions have an important bearing 
upon the fauna, it is relevant here to make a few remarks concerning 
them. 
The combined area of the main islands — Honshu, Kyushu, Shikoku, 
and Hokkaido — is 140,000 square miles, or approximately the same 
as the area of Montana. A large part of this area consists of moun- 
tainous country heavily forested with virgin and planted forests. 
Much of the land is worthless "hara," or rolling prairielike lands at 
the foot of the higher mountain ranges. These are densely covered 
with low, persistent bamboo grasses. Sand hills and plains along the 
coast also form a distinct habitat of considerable extent. About 17 
per cent of the total land area is estimated as arable, although only 
12 per cent is under actual cultivation. 
The limited area of arable land and the food supply demands of this 
densely populated country have made Japanese agriculture one of the 
most intensive in the world (fig. 35). Rice is the chief food and it is 
grown largely in flooded plots called " paddy fields," one-half of the 
agricultural lands being given over to this crop. The average land- 
holding in this agricultural area is 2J^ acres per individual. Where 
physiographical conditions were originally unfavorable, they have 
been altered if possible to suit rice growing. This has resulted in the 
terracing of hill and mountain sides and the cutting up of the low- 
lands into innumerable paddy fields to accommodate them to the 
varying water levels. Where it is possible to drain the paddy fields 
they are immediately prepared for wheat or barley as a successive 
crop. Areas not suited to rice culture are devoted to dry farming, 
including the growth of wheat, barley, rye, millet, soybeans, nd 
such vegetables as daikon radishes, eggplants, sweet potatoes, taro 
{Cdladium colocasia), and Japanese onions (negi). All these food 
plants, including such grains as wheat and rye, are cultivated and 
fertilized intensively during their growing period, and often eggplants, 
onions, or cucumbers are grown betweeen the rows of grain. 
On the island of Hokkaido, natural and agricultural conditions 
more nearly approach those of our Eastern States. There are large 
areas of natural forest similar in makeup to our own forests, the 
trees consisting of species of oak, maple, beech, magnolia, chestnut, 
birch, and pine. The extent of waste lands in Hokkaido compares 
with that of Pennsylvania. Agricultural landholdings in this region 
are somewhat larger than in Honshu and the method of cropping is 
similar to that in America. Corn, wheat, oats, barley, rye, millet, 
and some rice are the chief grains grown. Grasslands suitable for 
grazing are more abundant here than elsewhere in Japan, and dairy- 
ing and stock farming are resulting industries. 
Koiwai, near Morioka on the island of Honshu, is not in the 
zone of intense agriculture, but is in reality one large estate of 7,500 
acres in an old volcanic upland of sufficient elevation for the develop- 
ment of natural grasslands and grains, such as corn, wheat, and oats, 
and the methods of cropping are like those employed in the eastern 
