INSTITUTE, PUSA, FOR 1919-20 71 



There was no apparent reason why so many insects 

 should have been concentrated in individual plots in this 

 manner. The larvae of Chilo simplex were observed to occur 

 plentifully in the stems of Coix lachryma-jobi var. aquatica, 

 which was growing as a weed all over the Farm and 

 amongst the rice-plots, but all these experimental plots of 

 rice-plants seemed equally subject to their influence. The 

 concentration of the borers in individual plots seems there- 

 fore difficult to explain unless it was due to lateness of the 

 crop. 



From the above facts it would appear that Schoenobius 

 bipunctife?' and Chilo simplex, the former especially, are 

 more important than other borers in rice. The combined 

 effects of damage by borers in rice, however, in Bihar and 

 possibly in Bengal, does not seem to amount to very serious 

 proportions although even a loss of 4 or 5 per cent, in the 

 case of an extensive crop such as rice becomes a noteworthy 

 sum when expressed in money value. In the case of other 

 parts of India, notably Madras and Bombay, the damage 

 to rice by borers appears to be much greater, so far as we 

 have definite figures, but it would be very. desirable to obtain 

 more exact information. Even taking the annual loss by 

 borers at only 5 per cent, for the whole of India we find the 

 annual loss to be approximately four thousand seven hun- 

 dred millions of pounds of rice annually, and this figure 

 may probably be at least doubled when we consider the 

 total losses due to all rice-pests in India. 



The Halticine Chrysomelid beetle (C. S. 2043), men- 

 tioned in last year's report, has been observed to occur largely 

 on china (Panicum miliaceum). It is incapable of injuring 

 plants standing in water but may cause some damage to 

 dry -land paddy and millets. 



Sugarcane. Work was continued on the borers of 

 sugarcane and other cereals and also on other agents of 

 damage to these crops which produce effects similar to those 

 caused by the borers. The results obtained up to February 

 1919 have been incorporated in a paper by the present writer 



