158 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 5 



The six plots receiving two applications during this period produced 

 from 83.45 to 99.54% of sound fruit or an average of 97.65%. The 

 end wormy constitute about ^ of 1% (.308%). The average gain 

 during this period resulting from a second application was less than 

 ^ of 1% (.42%) which was accompanied by a slight reduction in the 

 percentage of end wormy. It was unfortunate that in 1910 no plot 

 received three applications and, as a consequence, the average percent- 

 age for this group is 99.22 of sound fruit, a yield undoubtedly relatively 

 higher than would have been the case if two plots for 1910 could have 

 been included. Even with this omission which, in a measure at least, 

 is favorable to three apphcations, the average percentage gained 

 between two and three treatments is only 1.57%. There is, however, 

 a marked reduction in the percentage of end wormy, it amounting 

 to only .185%o- 



The three plots receiving one late application during 1910 and 1911 

 gave an average percentage of sound fruit of only 77.47, there being 

 a variation between individual plots from 57.35 to 95.57. The average 

 percentage of sound fruit for these plots is approximately midway 

 between that obtained from one spraying just after the blossoms 

 fall and the yield on the check trees. The percentage of end 

 wormy (12.26%), is a great increase over that in the preceding 

 plots and shows in a convincing manner where this late spray lacks 

 efficiency. 



The check trees during this period gave an average percentage of 

 sound fruit of 68.78, the yield varying in individual plots from 28.41 

 to 85.06. The small yield of good fruit, it should be noted, occurred 

 on trees producing relatively few apples. The average percentage 

 of end wormy fruit for these plots is 20.95, a great increase in the 

 average for the plots receiving one late spraying and very different 

 from the data from sprayed plots where the greater number of wormy 

 apples have been injured by the second brood and are therefore side 

 wormy. 



A study of this data as a whole justifies the conclusion for the Hud- 

 son valley at least, that in normal years when the crop is abundant 

 or fairly abundant, one thorough early spraying, namely, within a 

 week or ten days after the blossoms fall, should result in the production 

 of 95 to 98% of sound fruit. A slight gain will accrue from a second 

 treatment about three weeks later, and an additional gain from a 

 third spraying given the latter part of July. The benefit from the 

 latter two is comparatively small, so far as the codling moth is con- 

 cerned, though ample to meet the cost of the poison and, in many 

 instances, probably the expense of treatment. Should there be suffi- 

 cient fungous disease to warrant applications for this purpose, there 



