THE CANADIAN ENTOMOLOGIST 



395 



taking the utmost pains that we were able to secure a fair measure 

 of control. 



In analyzing the results of this work we are unable to make 

 comparison with check plots, as the owner did not desire to leave 

 any trees untreated, and to have done so would have disturbed our 



sprayed plots to some extent, owing to the flying in of adults from 

 the untreated plots. It was, therefore, necessary to compare the 

 quantity and quality of apples obtained in 1917 with that obtained 

 in previous years, and further to compare this with the general 

 crop for the whole Valley over the same period. This is to make 

 certain that the results obtained actually represent the effects of 

 our work, and not of other factors which might have operated 

 over the entire district. Last of all, we wiir compare the results 

 obtained by our own work with those obtained on the portion 

 sprayed by the owner, as far as this is possible. In doing so, it 

 should be remembered that the conditions in that part were not 

 ideal for good work and that the comparative inexperience of the 

 man who did the spraying, would render effective control un- 

 likely. On the other hand, however, the infestation in this part 

 of the orchard was much lighter than the rest. 



Table No. 1 shows that in 1911 there was a phenomenally 

 large crop, following an abnormally low one of the previous year. 

 The crop of 1912 was also large, but since that year the fluctuations 

 have not been wide. 



