February, '17] ENTOMOLOGISTS' DISCUSSIONS 63 



fruit on the plots sprayed once was reduced from 27.67 to 9.68, and 

 that for the other plots in approximately the same ratio. This was 

 likewise true of the ''side injury" or "shallow" for the two years, so 

 far as these could be compared, owing to the fact that there was a 

 slight change in classification in 1916. The relationship between the 

 two types of injury was so close that a proportion showing the per- 

 centage reduction in the total wormy and giving the percentage of 

 "shallow" for one year would work out to very nearly the percentage 

 of "shallow" for the second year. This was true not only of plots 1 

 and 2, but of plot 3 and the check trees. The complete data are not 

 given here and the above is brought to notice as additional evidence 

 bearing upon this general problem. 



Generally speaking, the development of side injury is conditioned 

 upon the deposition of numerous eggs after the apples have become 

 an inch or so in diameter and smooth enough so as not to repel the 

 parent moth. We are satisfied that by far the greater benefit comes 

 from the sprajdng just after blossoming and that the "side injury" is 

 in general proportional to the infestation of the orchard. Moreover, 

 the probability of securing immediate results in checking this type of 

 mischief is not good and we look' for a material benefit from last 

 spring's treatment in reducing the probabilities of extensive side injury 

 in 1917. 



Vice-President G. A. Dean^ Is there an}^ discussion on this paper? 



Mr. E. D. Ball: I would like to ask Doctor Felt whether the 

 statement to the effect that the "shallows" are from larvse that later 

 went into the calyx cups is from experimental data. 



Mr. E. p. Felt: It depends a Httle on just what you mean by 

 experimental data. We examined in 1915 a great many apples show- 

 ing that type of injury. A considerable portion of them were empty, 

 and in a number of instances we found young larvse later working in 

 the calj^x. In one or two cases larvae were to be seen half way between 

 the "shallow" type of injury and the calyx and the mere fact that 

 you can find so much of this "shallow" tj^pe of injury with no indica- 

 tion of serious injury leads us to believe that this is the logical ex- 

 planation. 



Mr. E. D. Ball: These results do not agree with our western work, 

 but of course we did not work on any of those varieties of apples. We 

 call these marks "blinds" in the West. We consider where we find 

 a "blind" that it has been made by a larva which has died from some 

 cause or other, and this view seems to be pretty well established for 

 that region. When a young larva dies there is nothing left but the 

 black head. Often four or five of these " deadheads" (as we call them) 



