INSECTS INJURIOUS TO AGRICULTURE IN JAPAN 23 



Another chrysomelid upon apple, found most commonly in Nagano 

 Prefecture, though of general distribution, is Galerucella semifulva. 

 According to Takagi (176) there is only one generation a year, the 

 adults emerging in late June and early July and carrying over in 

 that stage until the following spring in rubbish and other places of 

 concealment. Upon emergence from hibernation in the spring these 

 adults oviposit at the margins of newly developed leaves. The larval 

 stage covers about one month, after which the larvae enter the soil 

 for pupation. The method of control used is the collection of adults 

 during the fall and early spring. 



Among the Scarabaeidae of Japan and Chosen the only species 

 of importance upon fruit trees is Holotrichia (Phyllophaga) dioin- 

 phalia (S). There is said to be one generation a year, though the 

 writer's investigations in that section have indicated a cycle of two, 

 or probably three years. The pupae transform to adults late in the 

 fall, and these remain in the soil until early in the following summer. 

 They are nocturnal in habit and when abundant strip the trees of 

 their foliage. The only measure of control thus far practiced is the 

 collection of the adults. 



The curculionid Hylobius gebleri (50, 132) is recorded as attack- 

 ing apple in the Aomori Prefecture in northern Honshu. There are 

 two broods per year, the first brood of adults appearing in May and 

 the second in September. The eggs are laid upon the underside of 

 the leaf, after which the leaf is rolled and the stalk cut. The affected 

 leaf dies and, after a few days, falls to the ground. The larvae feed 

 upon the dead leaf tissue and when mature leave it and pupate in 

 cells in the soil. Hibernation is in the mature larval stage in the 

 soil. The adults feed upon the buds. For control, the collection of 

 adults and the destruction of roiled leaves containing the eggs and 

 larvae are suggested. 



Eriocampoides (Galiroa) limacina (202)', the common pear slug of 

 Europe and North America, is very injurious to pear and apple in 

 Fukushima Prefecture. In this section two broods are produced each 

 year, and the winter is passed in the mature larval stage in the 

 cocoons in the soil. The life cycle of the first generation covers about 

 50 days in central Honshu. 



Another sawfly injurious to apple in Hokkaido and Chosen is 

 Hylotoma mali (73, 193). There are two broods a year in Hokkaido, 

 the adults appearing in June and the latter part of August. The 

 winter is passed in the mature larval stage in cocoons in the soil. 

 The eggs are laid singly in incisions in the margin of the leaf and 

 hatch in two weeks. The damage due to the feeding of the larvae 

 upon the foliage is at times very extensive. Though the cocoons are 

 usually formed in the soil they may frequently be found in dry grass 

 and rubbish and under buildings. Several means of control are 

 suggested, among which are shaking the larvae from the trees on to 

 cloths and killing them, the burning of rubbish in the orchards dur- 

 ing the summer and fall, providing pupation traps at the bases of 

 the trees and killing such larvae as assemble in them, and also tightly 

 closing places usually left open under the floors of houses and other 

 buildings in the orchards. The report of the Chosen station for 1917 

 states that this species has three generations in Chosen, the adults 



