390 PROCEEDINGS OF THE THIED ENTOMOLOGICAL MEETING 



The caterpillars were found in some numbers in grown-up sugarcanes 

 at Dacca in July and September, and have been observed at Pusa only 

 in small numbers in rice from July to November and in grown canes in 

 October. 



The larva closely resembles those of Diatrcea auricilia (C. S. 1574) 

 and Rice Chilo (C. S. 1677), but can be distinguished With the help of 

 the key. 



The full-grown larva is about 20 to 25 mm. long. The head is red- 

 brown, shiay. The prothoracic shield is almost similarly coloured as 

 the head and divided longitudinally ia the middle by a faint marking. 

 The general colour of the body is pale yellow. There are five brown 

 stripes on the back, one mid-dorsal and two on each side. In some 

 larvee there is a black band on the iimer side of the abdomiaal prolegs. 



The pupa is rather slender-looking compared with the pupae of the 

 other borers and either brownish-grey or brown in colour. On the head 

 end just above the eyes there is a transverse ridge the two ends of which 

 protrude slightly in the form of a pair of short horns. The prothoracic 

 spiracles are rather large arching ridges and the abdominal ones are 

 protuberant short tubes with clear holes. These characteristics dis- 

 tiuguish it altogether from the pupae of the other borers. 



The Rice Chilo (C. S. 1677). 



Plates 57,58. 



Foodplant — Rice. 



This species has not yet been observed to occur ia any other plant. 

 In the Insectary the larvae fed on maize and sugarcane stems. But it 

 was evident that they did not like these two plants and were compelled 

 to bore them in the absence of rice. 



As a general rule, the caterpillars hibernate in rice stubbles from about 

 the end of November to about March, the over- wintering larvae pupating 

 and emergiug as moths on a large scale in March to May. But moths 

 have been observed to emerge up to 12th November before winter and 

 on 5th, 13th and 20th January and 2nd, 18th, 20th, 25th and 28th 

 February. The early- emerging moths breed in early-sown rice ; larvae 

 have been collected in desaria rice in April. Up to about September 

 the larvae are found in rice in small numbers. They occur in large 

 numbers when rice comes into ear in October and November. This is 

 why we observe such large numbers of the larvaa in rice stubbles in 

 winter. 



