54 CIRCULAR 16 8, IT. S. DEPARTMENT OF AGRICULTURE 



southern and central parts of the island. Sugarcane is grown also 

 in Japan proper and in Chosen, but only on a small scale, as an 

 annual crop for food purposes, rather than for the production of 

 sugar. Consequently, all stalks are removed from the field before 

 the end of each season, this serving to restrict considerably the 

 increase of the various insect species which normally pass the winter 

 in the stalk. 



Ishida (38) lists the following six species as being the most 

 injurious among the sugarcane pests of Taiwan : Eucosma schistace- 

 ana, Ghilo infuscatellus, Diatraea striatalis, Scirpophaga auriflua, 

 Ligyrus rugiceps, and Oregma lanigera. He adds also various ter- 

 mites. Several others at times cause considerable damage. Mat- 

 sumura (94) gives an extended account of the more important species 

 in Taiwan. 



The tortricid Eucosma (Graph olitha) schistaceana is a serious 

 sugarcane pest throughout the islands of Okinawa (38) and is now 

 causing very extensive losses in Taiwan also (94), a large part of 

 the insect injury to the crop being attributed to this species. Five 

 generations are produced each year, breeding being practically con- 

 tinuous throughout the year. The eggs are laid singly upon the 

 leaves, and the young larvae feed upon the foliage, whereas the 

 older ones bore into the stem. Control methods consist in the col- 

 lection and distribution of parasites, the removal of infested stalks, 

 and the trapping of adult moths at lanterns. 



In the islands of Okinawa and Taiwan the pyralid borer Scirpo- 

 phaga auriflua (38, 94) often causes injury to sugarcane by boring 

 into the stem. Four rather irregular broods are produced each year, 

 the adults of the first appearing in March and those of the last in 

 November. Hibernation is in the mature larval stage. The eggs 

 are deposited upon the under side of the leaf and hatch in about 

 eight days. The larval stage lasts from 40 to 60 days and the pupal 

 stage 10 days. After hatching the larvae feed in the growing tip 

 of the shoot, later boring down into the stalk, and finally forming 

 the pupation chamber therein at a point 4 or 5 inches above the 

 ground. This may be recognized by the presence of an exit hole 

 at that point, the opening being covered by a thin film of silky 

 material. The greatest amount of injury is produced by the last two 

 generations. The growth of affected stalks is considerably retarded, 

 these averaging about 15 inches shorter than normal plants. Control 

 methods consist chiefly in the collection of adults by hand or at 

 lantern traps. According to Ishida and Moritsugu (39) this pest 

 has in recent years infested up to 12 per cent of the sugarcane in 

 Tainan Prefecture of Taiwan. 



A second pyralid, Diatraea striatalis (96) , causes serious injury to 

 sugarcane in Taiwan. It is known also as an important pest of this 

 plant in Java. There are four or five broods each year, and the 

 winter, which in this latitude produces merely a retardation of de- 

 velopment, is largely passed in the larval stage in the stalks. The 

 young larvae feed upon the new foliage and later bore into the stem. 



The noctuid Sesamia inferens (S. nonagriodes var. albiciliata 

 Snell.) is a pest of sugarcane as well as of many other field crops, 

 such as rice, corn, rye, and millet in Okinawa (38), as well as in 



