90 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



Plat I, which received all three applications of arsenate of lead, 

 gave 99.42 per cent fruit free from codling-moth injury, the per- 

 centage for individual trees ranging from 98.97 to 99.68. The total 

 number of apples counted from this plat was 86,467. Plat II 

 received the one-spray treatment and shows a total of 99.01 per cent 

 of fruit free from codling-moth injury, the percentages for individual 

 trees ranging from 98.67 to 99.70, and the total number of apples 

 examined being 51,150. This shows a difference of only 0.41 per cent 

 in favor of the demonstration. Plat III, the unsprayed plat, shows 

 84.50 per cent fruit free from codling-moth injury, the total number 

 of apples examined being 32,384. This shows a gain in sound fruit 

 by the demonstration treatment of 14.92 per cent, and by the one- 

 spray method a gain of 14.51. As will be noted, the percentages of 

 sound fruit from the check trees is rather high. This is probably 

 very largely due to the fact that these were located in the center of 

 the orchard, all the surrounding trees being sprayed. 



In Table III are shown the places of entrance into the apple of the 

 total larvae for the season for each tree of each plat, and also the 

 percentage, by plats, entering the fruit at the calyx, side, and stem. 



There was a total of 496 larvae on the demonstration plat, as 

 against 505 larvae on the one-spray plat, a difference of only 9 larvae 

 in favor of the demonstration plat. On the unsprayed plat there 

 was a total of 5,019 larvae. Comparing the percentages of larvae 

 entering at the calyx end of the apple on the different plats it will be 

 noted that the demonstration plat shows 33.06 per cent entering at the 

 calyx end as compared with 13.46 per cent on the one-spray plat. 

 The unsprayed plat shows 63.86 per cent of larvae entering at this 

 point, which may be taken to indicate the normal behavior of the 

 larvae. 



Table IV shows the comparative efficiency of the demonstration and 

 one-spray treatments in preventing infestation at calyx, side, and 

 stem. 



By comparing the figures for the different plats it will be seen that 

 the one-spray treatment was more effective than the demonstration 

 in preventing entrance at the calyx, and less effective in preventing 

 entrance at the side and stem. The demonstration treatment saved 

 a total of only 0.41 per cent more of the crop than the one-spray 

 method, most of this saving being due to prevention of side entrances. 



