INSECTS INJURIOUS TO AGRICULTURE IN JAPAN 31 



The pyralid Margaronia (Glyphodes) pylocdis is one of the most 

 serious pests of mulberry in Japan and Taiwan, extending its dis- 

 tribution to China and India. In Japan, according to Yokoyama 

 (212) who has studied the life history in some detail, there are 

 4 broods a year, though Maki (81) records 10 in Taiwan. The winter 

 is passed in the mature larval stage in cocoons in the soil or crevices 

 in the bark. The first adults appear in May. The eggs are laid on 

 the lower surface of the leaves and hatch in five or six days, the 

 young larvae feeding at first upon this leaf surface, and later fold- 

 ing the leaf. Control measures recommended are the collection of 

 adults at lantern traps, the trapping of hibernating larvae by wrap- 

 ping straw about the trunk, and spraying against the early stages 

 with a kerosene-soap emulsion containing pyrethrum powder. 



Boarmia (Hemerophila) atrilineata (6, 96\ 211) is one of the most 

 common of the Lepidoptera attacking mulberry in Japan, and it is 

 found also in Chosen and Taiwan. There are two broods of larvae 

 each year, and hibernation takes place in the third larval stage in 

 crevices in the trunk. The adults from the overwintered individuals 

 appear in early July and those of the following generation in early 

 September. In the early spring the hibernating larvae emerge and 

 begin to feed upon the buds and new leaves. Two additional molts 

 follow, and the cocoon is then formed among dead leaves on the 

 branches and twigs. The eggs are deposited in clusters upon the 

 leaves and young shoots. 



Diacrisia imparilis (5) feeds upon quite a wide range of plants, 

 but is particularly injurious to mulberry. There is one brood a 

 year, and the third-stage larvae pass the winter concealed in rubbish 

 beneath the tree. These appear early in the spring and feed upon 

 the young foliage. The adults emerge in July and deposit their eggs 

 in masses of several hundred on the undersides of the leaves. The 

 larvae are at first gregarious but later solitary. Control is effected by 

 the destruction of egg masses and young larvae and by the collection 

 of adults at lantern traps. 



The lymantriid Arctornis chrysorrhoea (listed as A. phaeorrhoea 

 Don. and Porthesia similis Fuess.) is a very common pest on mul- 

 berry, though it is not abundant enough to cause injury to the tree. 

 The importance of this species upon mulberry lies in the fact that 

 the urticating hairs of the caterpillars, some of which adhere to the 

 leaves, cause serious sickness to silkworms when they are fed with 

 such foliage (3, 126). 



Prodenia litura (81) is common upon mulberry in Taiwan and 

 southern China, and is recorded as attacking citrus and other plants 

 as well. There are said to be eight broods a year, and hibernation 

 is in the pupal stage in the soil. The eggs, which have a felted cover- 

 ing, are laid en masse upon the foliage. The young larvae feed upon 

 the lower leaf surface, whereas the older ones feed at the margin. 



The cerambycid borer Melanauster chinensis is mentioned as a 

 major pest of citrus occurring throughout Japan, Chosen, Taiwan, 

 and China. It is equally destructive to mulberry, the larvae boring 

 through the trunk and larger branches and at times killing the tree. 

 It is, however, a minor pest in Taiwan. Citrus, mulberry, fig, and 

 apple are the only fruit trees recorded as hosts of this pest. 



