CONTROL OF CODLING MOTH IN ARID REGIONS. 



63 



worms in the first brood in each orcliard, and without si)rayini>: the 

 results would, no doubt, have l)een nearly the same. 



That the late sprayings alone are not to be considered as a nieans 

 of controling the codling moth under badly infested conditions is 

 abundantly shown by the above results. Therefore their true vahie 

 to us is their killing power when apj)lied 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 ai'c averaged in Table X. 



Table X. — Rc.snlfs of time late .sprui/iii(/s on trees tluil Inid rvecived tiro iiirhj 

 ones, »V»(«r< tfc Hatcli orchard, I!JU.'/. 



Total num- 

 i)er of 



wormy ap- 

 ples. 



Two early sprayings 



Two early andthree late sprayings 



Worms killed 



Percentage killed 



417 

 112 



Number of Number of 



apples with apples with 



calyx sidt' 



wormy. wormy. 



106 

 36 



311 

 77 



306 

 71 



234 

 75 



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

 and the ])r()p()rtion 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 j)er cent is shown below : 



Table XI. — Rcfiiilt of three late s/irai/inf/s folloiriiu/ tiro earlii ones, Sniiirt c6 



l/dfeli orchard. Ifld.',. 



Total num- Number of Number of 

 ' ber of apples with apples w-ith 

 wormy ap- calyx side 



pies, second wormy, see- wormy, sec- 

 brood, ond brood, ond brood. 



Two early sprayings 



Two early and "three late sprayings 



Worms killed 



Percentage killed 



Tn 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. 



