CONTROL OF CODLING MOTH TN ARID REGIONS. 



63 



worms in the first brood in each orchard, and without spraying the 

 results would, no doubt, have been nearly the same. 



That the late sprayings alone are not to be considered a^ a means 

 of controling the codling moth under badly infested conditions is 

 abundantly shown by the above results. Therefore their true value 

 to us is their killing power when applied in connection with the early 

 sprayings, as shown below. 



In the third test the three late sprayings were applied to trees that 

 had received the two early sprayings. Three varieties were used and 

 gave similar results, which are averaged in Table X. 



Table X. — Results of three lute sprayings on trees that had received two early 

 ones. Smart & Hutch orchard. l ( ,)0' h 



Two early sprayings 



Two early and "three late spraying: 



Worms killed 



Percentage killed 



Total num- Number of Number of 



ber of 

 wormy ap- 

 ples. 



417 

 112 



apples with apples with 

 calyx side 



wormy. wormy. 



106 

 35 



311 



305 

 71 



234 



75 



The number of worms to be killed is much smaller than before, 

 and the proportion of " calyx wormy " to " side wormy " is reversed 

 as a result of the high killing power of the early spraying on the 

 calyx worms. The killing power of the late sprayings, however, was 

 only reduced 2 per cent below that shown when they were applied 

 alone. 



This experiment was repeated in 1905 with a still smaller number 

 of worms left after the two early sprayings. A still further decrease 

 in killing power of only 1 per cent is shown below : 



Table XI. — Result of three late sprayings following two early one 



Hatch orchard. 1905. 



Smart d- 



Two early sprayings 



Two early and three late sprayings 



Worms killed 



Percentage killed 



Total num- Number of Number of 

 ber of apples with apples with 

 wormy a p- calyx side 



pies, second wormy. sec- wormy, sec- 

 brood, ond brood, ond brood. 



16 



60 



In this case the number of " calyx wormy " was so small that the 

 results would have had to be expressed in fractions to have been 

 accurate. There were six sets in the experiment, and it is worthy 

 of note that on the two wormiest ones the highest killing power was 

 shown. 



