28 NEW YORK STATE MUSEUM 



barrels) from the wormy column and but 12,546 apples (31 J4 bar- 

 rels) from the end wormy. The two sprays, one given just after 

 blossoming and the second about three weeks later, reduced the 

 number of wormy apples by 28,686 (J2y 2 barrels) and the end 

 wormy by 20,441 (51 barrels). This latter is not very different 

 from the returns given by the first timely application, and in con- 

 nection with the data for one late spray, shows at once that the 

 latter is comparatively inefficient, so far as controlling codling moth 

 is concerned. The three treatments, one spraying just after blos- 

 soming, a second about three weeks later and a third the latter part 

 of July, eliminate from the wormy column 30,081 apples (75 bar- 

 rels) and from the end wormy 20,458 apples (51 barrels). 



It will be seen by referring to the above tabulation that the sec- 

 ond spraying resulted in a gain of only 1% barrels, while three 

 sprayings produced an additional gain over the two of but 2^ 

 barrels or a total gain over that secured from one application, of 

 4^4 barrels. The one late spraying eliminated only 39^ barrels 

 from the wormy column, a saving of approximately 4/7. The 

 above comparisons are based on approximate yields of an equal 

 number of trees, and in all instances except in the case of the trees 

 receiving the one late application, the total product of each plot 

 was approximately 100,000 apples or 250 barrels. The above tabu- 

 lations all show that by far the greater benefit resulting from spray 

 operations accrues from the one treatment given within a week or 

 ten days after the blossoms fall, and that the gains following sub- 

 sequent sprayings are relatively insignificant. We do not under- 

 take to imply thereby that one thorough timely spraying will con- 

 trol the codling moth satisfactorily in all sections of the country, 

 though we believe that the possibilities of one treatment have habit- 

 ually been underrated. 



Single spray experiments by others. It may be claimed by 

 some that the above returns from one spray are exceptional and 

 can not be duplicated under other conditions. Prof. A. L. Quaint- 

 ance of the federal bureau of entomology has recently compiled 

 figures showing returns from one application and experiments con- 

 ducted by him in different states over a period of several years. He 

 finds that the average of the percentages of sound fruit from one 

 spraying is 90.64 as compared with 96.19, the average of the per- 

 centages of sound fruit on the demonstration plots receiving from 

 three to five applications in one season. The unsprayed trees in his 

 experiments give an average of 57.79 per cent of worm-free apples. 



