4iU TROCEEDINGS OF THE TITIKD ENTOMOLOGICAL MEETING 



There has been no opportunity of examining Desaria paddy. Both 

 Aus and Aman varieties were kept under observation in different fields 

 a short description of which is given below. 



Dhougamma chaur is about 400 acres in area. About 100 acres 

 in the middle remains permanently under water. 



IJarpur chaur, about 250 acres in the area, is a somewhat marshy 

 land. 



Guzarmalla, a high land, is about 30 acres in area. 



Deopar Gonhri, a high land, is about 40 acres in area. 



Jhilli, a high land, is about 60 acres in area. 



Sweepers' plot, consisting of about one or two acres in area, is in 

 the trenching ground within the Pusa Estate. 



The method of examination was as follows ; Plots 5 yards x 5 yards 

 were marked out at different places in the fields and the plants which 

 showed " dead heart " or were dry within this area were counted. In 

 order to get an approximate number of the plants growing within 

 5 yards x 5 yards, the plants within an area of 1 yard X 1 yard anywhere 

 within the 5x5 area were counted. Plants standing in water as well 

 as in dry ground were selected for examination. The results of examina- 

 tion of the plants at various periods of their growth are given in Table 

 XII. The amount of damage in the different plots and in the different 

 fields varied, it being more in some and less in others. Table XII gives 

 an idea of average damage over large tracts. The damage hardly 

 exceeds about 4 per cent.* 



The results of the examination of stubbles in five of the fields men- 

 tioned above, excepting Dhougamma and Harpur chaurs, are given in 

 Table XIII. 



From the stubbles which showed signs of borer attack the percentage 

 of damage was calculated to vary from 14 to 55 in the various countings 

 and to be about 29 on the average. This percentage would indicate 

 the proportion of chaff in the harvested grain. Actually, however, as 

 will appear from Table XII, giving results of the examination of growing 

 rice, the damage at no period of the growth of the plants exceeded about 

 4 per cent, and usually it was much less than 2 per cent. All the four 

 principal borers, viz., S. inferens, Chilo simplex, Rice Chilo and Schosno- 

 bius bipunctifer, appear on a large scale in October-November when the 

 plants put forth ears. At this time a large number of young larvae of 

 all these borers is found in individual plants, the maximum number 



* It must be pointed out that this figure represents the state of affairs only in a 

 -email district in North Bihar. In other parts of India the damage is certainly much 

 greater. In Madras, for example, the average loss may be taken as ten per cent., repre- 

 senting a money value of approximately one hundred millions of rupees every year 

 iin this Presidency alone. 



