INSECTS INJURIOUS TO AGRICULTURE IN JAPAN 15 



eight or nine days. The larvae of this broocl feed upon the shoots 

 and half -grown fruit and reach maturity about the middle of July, 

 the adults emerging at the end of that month and early in August. 

 The eggs of this generation are laid upon the buds or upon the bark 

 of a near-by twig. The young larvae consume a few buds and then 

 spin a whitish cocoon within the last one eaten, and in this pass the 

 winter. 



The only control measures suggested are the bagging of the fruit 

 as soon as possible and the removal of infested clusters and twigs. 



There are a number of Noctuidae which in the adult stage suck 

 the juice from the ripening fruits of apple and pear after the paper 

 bags inclosing them have been removed. The most important of 

 these are Calpe (Oraesia) emarginata, O. excavata, and Ophideres 

 (Adris) tyr annus. They are major pests of these fruits in Chosen 

 {150) and China, though not so injurious in Japan. The feeding 

 punctures serve as points of infection for putrefactive organisms. 

 O threw {Ophideres) fullonica and Calpe capuvina are also mentioned 

 as attacking these fruits, though to a much lesser extent than the 

 above three species. 



Other insects injurious to the fruit itself, though not of so great 

 importance as those already discussed, are the curculionid Rhynohites 

 heros, the sawfly Hoplocamipa pyricola, and the mirid bug Hetero- 

 cordylus flavipes. 



Rhyncidtes heros is very abundant in the southwestern sections of 

 Hokkaido and also occurs in numbers in Honshu and Chosen. Ku- 

 wayama (73) has recorded the life history in Hokkaido, in which 

 locality the adults appear in the latter part of May. These feed 

 first upon the foliage and young shoots of apple, pear, and peach 

 and later upon the ripening fruit. The eggs are laid largely during 

 July in holes eaten into the surface of the fruit, and the stem of the 

 fruit is partially cut following oviposition so that the fruit will later 

 fall to the ground. When mature, the larvae leave the fruit and 

 enter the soil for hibernation, passing the winter in the larval stage 

 and pupating in the early spring. 



Muramatsu {107) has studied the life history in Chosen, and there 

 the adults appear about the middle of June. The eggs hatch in one 

 week. After leaving the fallen fruits, the larvae enter the soil and 

 feed upon the roots of various weeds and vegetables. The winter is 

 passed in this stage, and pupation occurs in May. 



Control measures employed when necessary are the collection of 

 adults by shaking them from the tree on to cloths, bagging of the 

 young fruit, the destruction of infested and fallen fruit, and spray- 

 ing with a preparation containing naphtha, insect powder, and soap. 

 Poison sprays are also extensively used in Japan. 

 t The apple blossom weevil of Europe, Anthonomus pomorumi, is at 

 times a serious pest of Japanese pear (Pyrws serotina) both in Japan 

 and Chosen. According to Murata (109), a single generation is pro- 

 duced each year, and the winter is passed in the adult stage. These 

 adults come out of hibernation in the spring and in April deposit 

 their eggs in holes eaten into the flower buds. The eggs hatch in 

 from seven to nine days. The contents of the buds are entirely con- 

 sumed by the larvae, and pupation occurs in the chamber formed 

 therein. The adults from these usually emerge during June. 



