REPORT OF THE SOCIETY 



135 



The results of the experiment are shown in the following tables. 



TABLE IV. 

 Percentage of Caterpillars in Sprayed and Unsprayed Plots, June 10th to 12th 



1 One tree in this plot gave an exceptionally high count, while the others were uniformly 

 low in the percentage of infestation. Including this tree, the average count was 6.6 and the 

 reduction 65 .8; excluding it as an abnormal tree, the figures are 2 .5 and 87 .0, more nearly 

 what would be expected. 



2 The percentage of lar\'ae on this plot was higher than that found on the plots sprayed 

 with either 2 or 3 alone. The probable explanation of this anomaly is that the local area in 

 the orchard was worse infe^ed originally than the other parts of the orchard. 



From the tables it will be seen that the spray applied as soon as the 

 leaves were fully expanded was the most effective of any single spray. That 

 applied just before the petals spread was next in efTectiveness. The spray 

 applied as soon as the insects began to enter the buds was not very effective. 

 The fourth spray was not used alone but its effect in combination may be 

 seen from the tables. 



Where the usual spray calendar is followed thereshouldbelittledifificulty 

 in keeping this insect in check as the second and third sprays in the calendar 

 correspond to the third and fourth sprays given above, and it will be observed 

 on referring to the figures that these formed the best two-spray combination. 

 These results agree with those obtained by Mr. G. E. Sanders in Nova 

 Scotia. 



In 1916 onehundred treesin the same orchard were used in the spraying 

 experiments. Except those that were left as checks the trees were all given 

 two sprays, one about three days before the blossoms opened and one after 

 the petals had fallen. 



