REPORT OF THE STATE ENTOMOLOGIST I9I2 



23 



amount placed upon the foliage if a second spraying be given dur- 

 ing this period, as will be seen shortly, is of comparatively small 

 value in destroying codling moth larvae. 



Summary of four years' work with one spray for the codling moth 











CLEAN 



FRUIT 



WORMY FRUIT 



PLOT 



•SERIES 



YEAR 



TOTAL 













End 





Per 









FRUIT 



Total 



Per 



Total 



Per 



End 



and 



Side 



cent 











cent 



cent 



wormy 



side 



wormy 



end 





















wormy 





wormy 



I 



I 



1909 



30177 



29818 



98.81 



359 



1. 19 



33 



18 



308 





4 



I 



1909 



20313 



20017 



98.55 



296 



1-45 



31 



6 



259 



I 



2 



1909 



21264 



21042 



98.96 



222 



1.04 



23 



18 



i8r 





4 



2 



1909 



9852 



9683 



98.27 



169 



1.73 



19 



13 



137 





7 



2 



1909 



1909I 



18617 



97.52 



474 



2.48 



SI 



32 



391 





I 



I 



I9IO 



1839 



1664 



90.48 



175 



952 



16 



21 



138 



I 



2 



I9IO 



8135 



6677 



82.08 



1458 



17.92 



160 



27 



1271 



I. , 



I 



I9II 



16638 



16515 



99.26 



123 



• 74 



19 



12 



92! 



I 



2 



I9II 



20802 



20401 



98.07 



401 



1.93 



28 



14 



359 



I 



I 



I912 



III38 



10833 



97.26 



305 



2.74 



14 



16 



275I 



2 



2 



I912 



10029 



9898 



98.69 



131 



1. 31 



13 



13 



105 



Grand to 



tal 



169278 



16516s 



97.56 



4113 



2.44 



407 



190 



3516 .^sl 











The above tabulation shows that one spray during this period 

 produced from 82.08 to 99.26 per cent of sound fruit or 

 an average of 97.56 per cent for the four years, when comparisons 

 are made between an equal number of plots in each year. In ex- 

 planation it should be stated that the figures for several plots in 

 1909 were omitted simply to give a more nearly equivalent value to 

 the returns obtained for the four-year period. Attention should be 

 called to the low percentages of 1910, a season remarkable for. the 

 unusual destructiveness of the second brood and one presenting 

 infrequent conditions which were further accentuated by the small 

 yield of that year. Excluding the data for 1910, the lowest per- 

 centage of sound fruit obtained from one spraying was 97.52. It 

 is worthy of note that only a little over ^ of i per cent (.353 per 

 cent) of the wormy apples were end wormy. This, compared with 

 the proportion of end wormy on the unsprayed trees, which latter 

 amounts to 21.73 P^^ cent, shows that the great reduction in wormy 

 fruit was due to the destruction of the caterpillars or apple worms 

 attempting to enter the apples at the blossom end, and indicates in 

 a striking manner the importance of this early spray. The contrast 

 is more evident if we raise the yield of the check or unsprayed trees 

 to approximately that of the sprayed trees and the other data pro 



