INSECTS INJURIOUS TO AGRICULTURE IN JAPAN 61 



are six broods each year, and the winter is passed in the larval stage. 

 The duration of the egg, larval, and pupal stages under summer 

 conditions is from 2 to 3, 14 to 21, and 8 days, respectively. Con- 

 trol measures advocated are the planting of Indian rather than 

 American varieties and the removal and destruction of rolled leaves 

 containing larvae found upon the plants in the field. 



Glyphodes indica (95) has three broods a year in Japan and 

 hibernates as a partially developed larva. Feeding takes place upon 

 the foliage of various plants in the early spring, and pupation is in 

 the rolled leaves. The second and third broods feed upon cotton 

 foliage. The adults of the three broods appear in late May, early 

 July, and the middle of August, respectively. 



The pyralid Hypsipyla forrnosana (167) is confined in distribu- 

 tion largely to the eastern sections of Taiwan. Little is known re- 

 garding its habits except that the larvae feed upon the developing 

 seed. 



The cotton seed weevil, Araecerus fasciculatus (167), a more or 

 less cosmopolitan species, is found in Taiwan but is restricted to the 

 southern sections about Ako. The adults are present in the field 

 from July to October, and the larvae feed upon the seed. 



The curculionid Hypomeces squamosus (167) is common in 

 Taiwan and China as a minor pest of cotton, the adults feeding 

 upon the foliage. The larvae probably develop upon some other 

 plant, and their habits are unknown. 



The large mole cricket Brachytrypes portentosus (listed in early 

 literature as B. achatinus Stal and Liogryllm formosanus Mats.) 

 (167, 172) is one of the common pests of cotton in Taiwan, particu- 

 larly in the coastal sections which have a rather sandy soil. Upon 

 cotton the injury is primarily to the young plants, the leaves being 

 cut off and carried down into the burrow. 



The cotton stainer Dysdercus cingulatus (167) is found in 

 Taiwan and Okinawa and is an important pest. Both the nymphs 

 and adults feed upon the sap of the plant, particularly at the bolls. 

 It is controlled to a certain extent by a tachinid parasite. 



Probably ranking next to the pink bollworm in the injury inflicted 

 to cotton is the red spider Tetranyclius telariws, which has a number 

 of additional food plants. It is most abundant during August, fol- 

 lowing the ending of the rainy season, and increases rapidly during 

 hot, dry periods. During such times it is often the cause of com- 

 plete defoliation and the death of the plants. The control measures 

 recommended are the elimination of weeds along the field borders 

 and of beans between the rows, and in exceptional cases spraying 

 with lime-sulphur. 



The other pests listed are more or less general feeders, and their 

 attacks upon cotton are not serious except in the case of occasional 

 outbreaks. 



TOBACCO INSECTS 



The noctuid Pyrrhia umbra (1J$) often causes considerable dam- 

 age to tobacco in Japan. An account of this species is given among 

 the insect pests of legumes (p. 68). In both Japan and Taiwan 

 the greatest insect injury to tobacco is due to the attacks of the 

 various cutworms. Several other insects are listed as attacking 

 tobacco, but they are not responsible for serious injury. 



