74 SCIENTIFIC REPORTS OF THE AGRICULTURAL RESEARCH 



acres) and Sathi No. 15 (a little less than one acre). 

 There are also very small plots of other thick varieties,. 

 e.g., Kaludaie Budhan, Dacca Cane, D-99 and Ashy Mauri- 

 tius. A little more than one acre is under 21 different 

 varieties which are classed as thin canes but some of them, 

 e.g., Meneria, might be described as of medium thickness.. 

 Of the half acre under Purple Mauritius \ acre was planted 

 in November 1916; the other half of the Purple Mauritius- 

 and all the rest were planted in February, 1917. The plot 

 of Purple Mauritius has been specially grown for entomo- 

 logical observation and experiment and this cane has always 

 been critically examined while the others have been super- 

 ficially examined for comparison of results. All the time 

 the sugarcane has been in the field there have been maize and 

 juar growing somewhere in the Farm. The progress of 

 the insects in sugarcane, maize and juar has been careful lv 

 watched and is briefly described below. Red Rot in sugar- 

 cane has necessarily come under observation and there has 

 been a good opportunity of comparing the damage caused 

 by it with that caused by insects. 



In the middle of April the plants of the plot of Purple 

 Mauritius planted in November were slightly ahead in 

 growth of those of the plot planted in February, but the 

 difference in growth did not indicate a difference of about 

 four months in planting. The damage noticed about this 

 time was almost wholly due to insects and the damage in 

 the former plot was 6-3 per cent, while in the latter plot it 

 was 23 per cent. Taking both the plots together, of the 

 total damage : 



Scirpophaga xanthogastrella was responsible for 1-7 per 

 cent. 



Diatrcea suppressalis for 2-3 per cent. 



Gryllotalpa africana for 0-1 per cent. 



Red Rot for 0-22 per cent. 

 All the affected plants were cut out and destroyed with the 

 insects. All this time Chilo simplex and Sesamia inf evens 

 were abundant in Rabi maize and in a very small extent in 

 Rabi juar. 



