April, '08] JOURNAL OF ECONOMIC ENTOMOLOGY 135 



plot isolated as already described by surrounding trees similarly 

 treated, and preferably 10 trees should be counted, for it wiU be found 

 that the records of five individual trees will vary fully as much as the 

 average of one plot and another. All of these factors are therefore 

 of the utmost importance and it becomes a considerable undertaking 

 to make a careful experiment on this subject, the amount of the work 

 depending very largely upon how much competent labor can be se- 

 cured to make the records. It is needless to say that in our work 

 every dropped and picked fruit has been examined and a record has 

 been made as to whether it was wormy and whether the larva entered 

 the calyx or the side. 



It is not my purpose to give any extended discussion of the results 

 of our work of this season, but to briefly report my conclusions. The 

 fuU data upon which they are based will be published later. Fig. 4 

 shows the plan of the orchard. 



The results of our work have been computed in percentages thru- 

 out. This is not the place to discuss our method of computing the re- 

 sults, but suffice it to say that after having compared the number of 

 wormy apples to the number of apples on the tree and the percentage 

 of wormy apples, we find that the percentage wormy is a much more 

 reliable basis for comparison than the number of wormy apples them- 

 selves. Our conclusions are based on a study of detailed records of a 

 total of about 400 trees, covering two seasons, and including a count 

 of over 350,000 apples each year. 



Plot 1 was given the third spraying (the third spraying being that 

 immediately after the petals fall, the fourth spraying 10 days later 

 and the fifth spraying about three weeks after the petals fall or when 

 the eggs are hatching) with a fine mist. Plot 2 was sprayed at the 

 same time with a Bordeaux nozzle and thoroly drenched, the spray 

 being applied at 100 lb. pressure. Neither of the plots were sprayed 

 subsequently. This experiment was repeated under similar condi- 

 tions in another orchard. There was but 2% or 3% difference in the 

 result in both cases, in one orchard the result favoring the drenching 

 and in the other favoring the mist, so that we are forced to the con- 

 clusion that there is very little difference in their effectiveness. Care- 

 ful examination of the calices by Dr. Headlee failed to show any spray 

 lodged beneath the stamens or in the calyx cavity proper, nor did he 

 find any dead larvae in the calyx cavity proper tho the results achieved 

 by our spraying show very clearly that it was exceedingly effective. 



Fig. 4. Diagram of orchard of Oilman Woodman, Durham, N. H., used in 

 experiments of 1907. Plots A, 1, 2, 3, 4, 5, 6, experimental sprayed plots; 

 plot 3, "barrier" plot; plot C, "check" plot, unsprayed. 



